As much as many transwomen want to keep their wives, the only way I see it working is if she's either consciously or unconsciously bisexual. If she's the kind of woman that loves someone for who they are, regardless of their sex (some women like this are unconsciously bisexual.) If she's not bisexual and not comfortable with being seen as lesbian, it's not going to work out eventually.
Fact is that a heterosexual woman wants a man. This is the unfortunate truth about many trans people, that we have unintentionally and unconsciously lied to everyone around us. With lies comes the consequences of lying. Even if we had a choice, many of us initially would have lied for fear of losing friends, family, and for fear of being an outcast, which are understandable reasons. This is what society has done to us, just as it had done to so many gay people long ago. By preventing or making it hostile for people to be whoever they are, they make people like us to unintentionally hurt or disappoint others around us because we didn't have the opportunity or the courage to find ourselves and live as who we really are in large part because of society not being as friendly toward people who didn't conform to their birth sex. It's not our fault, it's society's fault, for pushing people to conform to whatever society wants people to be (and moreso for genetic males than females) especially in the past.