Gordie, my W and I reached the same stalemate in August. Being the nice guy, I left the mbr in July when she went to see OM the first time. After the second OM visit in August I moved back into the mbr and told her she could leave it if she wanted but it was not fair to me to not be in my bed.
5 months later we are still in the stalemate, though we have not discussed it in months. Don't know that there's anything you can do if she refuses to leave the mbr. For you, I don't see any reason you should leave as this is her decision. If she really needs to be away from you then she can leave. Not your circus.
Don't anticipate anything. It's ok to strengthen yourself to face the unknown but worrying about what may happen will only drive you nuts. Run scenarios through your head and how you would react but don't dwell on the what ifs. Almost like a coach game planning for a football game. Do it as dispassionately as is possible. Again, her facing reality is her circus, not yours. No need to worry about how she reacts to it. Just worry about you and being there for your kids.
Me39 M11 : T13 D9 BD 5/31/16 In House S until 6/21/17 Divorced 10/5/18