My wife and I are still married, 15 years before transition, ~3 years since I came out and started dressing, 2 years of HRT. I have two children from a previous marriage, 35 and 26, both are lawyers.
My kids have been awesome, but they are both politically liberal.
I can tell you one thing, though. HRT may save your marriage. The psychological effects can be awesome. I know they were for me. HRT ended a lifetime of chronic anxiety, sleepwalking, nightmares, and ten years of chest pains, irregular heartbeats, high blood pressure and massive debilitating panic attacks. I went from being constantly grumpy and irritable, constantly seeking the next hobby, experience or diversion, to my wife and me always having fun together.
If I have to wear any article of male clothing, even to do yard work, or present male for some reason (like non accepting family members) I get grumpy and irritable.
If I let my estrogen get too low, or forget to take an anti androgen pill, the panic attacks return with stunning rapidity.
I held off transitioning as long as I could, and doing so nearly killed me. Why compromise quality of life in the name of appearances? Let your spouse transition and be happy. You may find in her, all the good qualities you married him for. You may find your best friend. You may find the love of your life.