I know you said she wouldn't consider Retrouvaille. But it is stuck in my head that unless a couple tries Retrouvaille they haven't done everything they could to stave off divorce. As long as you are giving ultimatums, maybe you could make that one of the options. Counseling or a retrouvaille weekend and post sessions. It's a limited time period. The whole thing would be done in 2 months vs. counseling which is unlimited. So it could be an attractive alternative. And it is so worthwhile. Even if you do end up divorced, you have much better communication between you to deal with whatever comes up.