I misjudged the electorate once, badly, and given that I think he's been a lot less harmful than I thought he might be so far, I'm not convinced that I wouldn't be totally wrong again if I thought anything that's happened in the last three years would change the minds of most people who voted for him. Regardless of whether most Trump voters are in fact deplorable, I suspect they're unredeemable with Fox still on the air and Republicans putting party over principles.
Plus, it may take a landslide for Republicans not to back him contesting the election if he loses. I'm sure a lot of them secretly want this regime to end, but they've mostly gone all in, and won't have many chips left in their pockets to go home with if they don't stay in until the end.
I wouldn't be totally surprised if Trump tries to secretly cut a no prosecution deal in exchange for not screaming about voter fraud, even then, really. He's certainly set it up with his base already and Putin would love it.
I'm predicting that it'll all come down to new voter turnout, plus fewer protest votes to third party candidates, near perfect execution by Democrats in the general, economic unease at home and a combination of help/and or lack of help from overseas to have anything close to a normal transition of power and start rebuilding the damage he's done.
On the subject of what Trump actually wants, I think you're probably right that at some level, he's probably tired, but I don't think his ego will let him just lose quietly without making it into something he can call a win.
I'll bet he'd need an exit plan, at least a cover, or better yet, a deal that protects him or lines his pockets to slink off.