Well, for some it works, but sadly for others, it does not. One thing I learned from my first marriage is that we all enter with a preconceived notion of how the relationship should be. However, some of those notions are just unworkable in real life.
It should be obvious to all what an upheaval that the spouses have to deal with. There isn’t much allowance for not being the person that she thought you were. There are couples that stay together after transition. I know of at least 2 here in town. Also, my wife and I have stayed together, but my case is a bit different. I have essentially transitioned socially, but I never did have any plans for surgeries. I have never seen any statistics, but anecdotally I suspect that the majority of folks do separate.
Since there is no fixing it, that says that the only thing to do is move forward. What else is there?