RL, I'm very glad that you've made a decision about your situation. Your h hasn't been a happy man for quite some time, especially since his return from Russia. You've handled your situation w/grace and dignity and he doesn't realize just how lucky he has been to have you as a friend, companion and spouse.
I'm also glad that you spoke to his family about the situation and I do believe that they will always be there for you as family and friends. I wouldn't worry too much about that as they've responded very well to the situation, especially his mother.
While he is a civil mood, please get the papers drawn up because you don't want him to have a lot of time to think about things, especially financially and you do not want the RT to fill his head w/stuff about what to agree or not agree to. It will be good for him to go back to Russia and live out his fantasy w/o any strings to hold him here. He needs to continue on his journey and finish it up, i.e., wherever that may be. As for the RT, she's not going to be happy w/him coming over there because she wanted it the other way around. Oh, well...it's his fantasy and he will do what he must do to continue moving forward on his journey.
Now, it is time for RL to think about what she wants to do. The old year certainly ended on a bang w/surprises and I know the new year will be full of additional surprises and hopefully they will be all good.
You fought for your marriage and unfortunately it couldn't be won, but you certainly have grown by leaps and bounds and you've discovered a new RL in the process. You are a survivor and certainly not a failure. The world is waiting w/open arms for you to begin your new and exciting life.
You are going to be just fine.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.