I, too, have a friend in RL whose H was away for 5+ years, lived with an OW for 2 or so of those.... he's been back for many years now, yes it took time, but they no longer even remember the MLC years. He's the same, but better -- shows insight into himself. He hasn't magically turned into super-H, but is himself, with all quirks and so on.
I know of other cases personally as well.
And as to finding someone else, even not thinking about the odds, it's not just about me any more. I have kids, who would also be affected. They're hurting, too. And my happiness isn't their responsibility. I've lived that with my own parents, even if in one case I like the new person, and it's still awful, even 30 years later.
And I like myself now. I'm healing, even if all this is still awful.
On the other subject, my first thought when H left was 'brainwashing', as he'd been to a new age weekend right before BD. Goodness what cans of worms they opened up.