Our situations are very similar. My RAH(for now), also an intelligent professional (retired pilot) made a fool out of himself at a family occasion-- not unusual for him over the last 30 years or so -- and I told him he had to move out for at least a year. He did and I'm debating about what to do about housing for both of us if I decide he can't move back, which is the way I'm leaning. Due to other circumstances he's caused, I don't think I can ever live with him again.
It's always good to have your ducks lined up and know what your options are. The housing situation for me has been one of the biggest issues. Maintaining two households is expensive. Downsizing sounds like a good idea. But I love my house, we owe very little on it, I'd probably just refinance it to lower my payments. My husband is retired, I'm close to it, I'm not interested really in divorce, just permanent separation.
Don't make any decisions too quickly.