Just to throw my experience out there--
I decided to divorce XAH when he wouldn't come home and was getting deeper into drinking, drugs, and the OW...
One week after our divorce he married her, our kids were a wreck, and when I tried to discuss it with him he said "things might have turned out differently if you hadn't left". Implying that he and I would still be married and he wouldn't have "had to marry her because he was lonely", as he told the kids. I KNEW that if I hadn't left, he and I would still be married, and he'd still be with her and not coming home. So that's a line of crap.
One of my best friends said the switch flipped in her head when her H said, "I just can't decide who I love more". She said- I'm your WIFE. There isn't a decision to be made here. And she walked away. He married the OW.
In my experience guys like this NEED someone to hold on to. So I second the thought that he may grasp at you as you leave (mine did), but if you stick to it, don't be shocked if he turns up remarried quickly. It has nothing to do with you. And it never will, even if you stay. You deserve so much better!!!
Enjoy your trip!