@tps26
First:
the usual warnings and caveats. I don't know you or your wife or your personalities or histories. There is a lot more going on here than I can tell from a short description. So any commentary is based on partial information and may well steer you wrong. I can only advice based on what you tell me.
Second:
she has determined to withhold physical contact. When I seek to mediate this attitude with her, she does not want to discuss my position without a "lawyer or counselor", She has given a number of ultimatums of the final sort. However, she still likes to chat about typical day to day stuff, which makes me feel a little used for emotional support with no real affection.
WARNING
The last guy here this happened to had his wife up and leave him (contrary to her reassurances), taking the kids out of the country. You need to get a lawyer and plan accordingly and take steps to preserve your position. You must presume she is getting ready to drain the bank account and abscond with the kids or kick you out and call the cops on you (making false allegations of abuse in order to keep you away and alienate you from the children). Pray it doesn't happen. But a wife who refuses physical contact has defrauded you of your marital rights and is hardening her heart against you. It's part of her mental preparation to leave. The marriage is dead man walking. You might be able to save it (esp. if this is a bluff/power play) but prepare for the worst.
Treat this as an emergency situation.
Third:
I wouldn't expect bringing up the subject of poly twice in 3 years go cause a woman to nuke the relationship like this. I feel like we're missing something. A few background questions:
Is there another woman in the picture or history of that?
Is this the first marriage for both of you?
How long have you been married? How old is your youngest?
Is it possible she's cheating on you?
What do you mean by "supress my intentions"? Have you made it clear to her you intend to add another wife?
Is her issue with polygamy or with you wanting a patriarchal dynamic to the marriage (you the head and her in submission)? My answer below assume the big issue is about you wanting to add a second wife. But I feel like there is a lot more going on.
What was the leadership dynamic in you marriage before?
Is she suffering from depression or have a history of mental illness?
Have you been making other changes to relationship dynamics in this time?
"away from home for some lengths of time" how much?
What is the content of her ultimatums?
The answer to these could greatly change my advice that follows; esp. the last question.
Forth:
As to your questions...
ants me to heavily consider the implied understanding my wife had when entering a western marriage (despite my self-written vows being providentially biblical)
In anything other than marriage, implied and verbal understandings are null and void; only the vow / contract itself governs the terms. What you are finding is what all men going into divorce find: the vow is only binding on you, not her. Don't expect your elder to understand that or push the wife to uphold her end of the bargain.
That said he is kind of right. The social contract of marriage in the west, what's left of it, presumes monogamy. She really did marry you with that understanding. You really are changing the foundational understanding of the marriage.
1. Do nothing, let her work it out in her heart or leave of her own will. Put it in God's sovereign hands, and trust his purposes. Downside to this is that zero physical contact is damaging in the interim, and I risk the future of my children.
That's the naive passive nice approach; never a good option. God's sovereign will was you be the spiritual leader of your wife and it sounds like you really messed that up. Pray, pray, pray. And fast too. But in the end its up to you to turn this ship around.
Being passive likely won't work out in your favor because her going no physical contact is part of her severing the bonding between you in preparation for leaving. Left unchecked, her internal bitterness at her perceived betrayal by you will kill the marriage. If it's not already dead.
It could be a powerplay to bring you to heel. But it's more likely she is hurting (bad) and despises you for 'doing this to her'.
2. Sit down with her and an elder or two, hope they know the bible and don't care more for the traditions of men. At least this would give me a chance to speak my mind without her walking away from me. There are good, solid people in my church that I trust more than most other churches I have been to. (But it's a little repulsive to me to consider taking grievances before other households that should be handled internally)
99% of the time they'll take her side. You better know going in their stance and how they'll handle her. But if its not the elders from your church community, and men she respects, with the backing of the church women, it's likely not to work. And it's common anyway for women to ignore elders and therapists who don't validate their feelings on the matter. Which is why marriage counseling is usually worse than useless; most therapists just validate her worst impulses and if they don't she stops going.
3. ...withhold my presence and emotional companionship until she seeks me out... or leaves...
I'm not a big expert on this move but so far as I perceive it, withholding time and attention will not work on a wife who has checked out of the relationship and/or is planning an exit. It's more applicable before it goes that far (but maybe I'm wrong). There is a variation on this which has been used by men in seperation/divorce, that is to go cold turkey on her and don't communicate at all except by lawyer (as opposed to begging and pleading and trying to communicate or being her friend) as its the only chance you have via a 'absence makes the heart grow fonder' affect. But it's a hail mary.
That said, being her friend (so far as she allows) but not having affection (so far as she doesn't allow) WILL NOT WORK.
So maybe withholding affection could still work? I don't know. Maybe only if you call her bluff; some men hand her divorce papers when she threatens it to call her bluff, and then establish new parameters for behavior when she blinks, high stakes and theologically questionable but sometimes works.
3. Take a stand to her behaviour. Rebuke her attitude as lovingly as I can, and withhold my presence and emotional companionship until she seeks me out... or leaves...
So here is the thing, it is very likely she's checked out of the relationship (I can't tell for sure from here, but cutting off affection is the key symptom, that and not caring anymore about you/the relationship, as is the insistence on lawyers). You will not be able to restore the marriage until you get her to care again, to be in favor of you again. And given your long work absences, she's used to not having you give her time/attention.
Some men have pulled women back from that brink by pure force of will, taking a stand and insisting on her behaving properly as a wife so long as she is there (specifically with regards to her being willing to talk to you about things and show affection) and enforcing your will. If you can pull that off and get her operating as your wife again, it can give you chance to work on her bonding and being a better leader yourself. This is the only approach (other than calling her bluff & then enforcing your will), that I can recall working once marriages get to this point.
That said, it sounds as if she absolutely won't do poly and you absolutely will and so you're at a standoff that will not be resolved. You won't logic her out of it nor force her hand. The pure force of will likely won't get her to accept poly so I wouldn't make it about that. But you may be able to get a truce on the basis that your desire for poly is purely academic until you actually have another woman. Which would give you some time to work on your relationship with her / decide if you really want to go this route. The talking about things should not be poly, you need to reestablish a firm foundation of attraction and leadership before that becomes a topic again.
Which brings me to...
Fifth:
Are you sure poly is really the way you should go? You need a gut check about where things really stand here. She's checked out and is withholding affection. She's doing this because she feels hurt and betrayed by you for violating your mutually held foundational understandings on marriage. You've sprung this on her with no opportunity to talk about it or have a say or discuss or get used to is or adjust; just decided it. And her response has been to nuke the relationship.
All that speaks of a husband who quite possibly....1) mishandled the situation very badly, 2) didn't understand his wife, 3) hasn't been a good spiritual leader, 4) isn't the head of his family, 5) has allowed his wife's attraction/bonding to him falter, and 6) has been away from home more than is healthy for his relationship.
In other words you messed up your responsibility to God as a husband. You're not ready for poly because you couldn't handle monogamy. Poly is great and all but you need to be able to be a good husband to 1 wife before you can think of being a husband to 2. Fix this situation, become a better husband, and then consider poly later. Repent to God and to your wife for failing as a husband and then be better.