It sounds like she's preparing to waffle out of the weekend if at all possible. Be prepared for that. If she does, I wouldn't just go somewhere and have fun with her. If she doesn't choose to work on your marriage, then I think you will have to pull back, detach, and stop the cake-eating. Even if she does go, you need to try to remain detached, be strong, no one weekend is going to make or break your marriage.
Your W sounds like a typical WAS mess, and like living on a rollercoaster. You need to detach from that, so you don't have so many ups and downs....
