I'd bet hard on it. But I'd bet that he stays.
His ego will not allow him to back down. We've seen it before time and time again. He can't admit that he is wrong about anything. He's lied about things he said, about things he did, and about things he was told. And when he gets caught in a lie, instead of admitting it was a lie or apologizing, he just acts like it wasn't a big deal. So why would he turn tail now?
Hell, he thought that he was going to lose four years ago. He was setting the table to be a petty loser, because that was his plan all along. He's had plenty of time and chances to back out or "quit" this whole time, and every time he just doubles down on the crazy.
The only way that he would quit before November is if someone concocts a plan that gets him out of the shitstorm of trouble that he'll be in as soon as he isn't president anymore. If someone creates an exit strategy for him that keeps him out of jail and/or poverty, he might BS some reason to "step down". Otherwise, he's just going to whine and lash out for another 4 months, then (hopefully) whine and mope for another two months, then (hopefully) pack his shit and go in January.
(Side note: I could maybe see him dipping out early post-election. He's that kind of petty to just do that or just spend the rest of his term golfing or something...)