I'm going to remain highly skeptical, and I suspect he's more likely to stay on until he's forced out or loses in 2020.
With that said: can you imagine how the GOP would react if Trump voluntarily resigned? They'd try to put a brave face on it by insisting that he was driven out by a witch hunt (read: law enforcement and the courts doing their jobs), but you know they'd be freaking out in private. It doesn't look good to put so much blind faith in a leader only to have him quit because he doesn't like having his scummy behavior held under a microscope.
I doubt this. While I'd expect their outward statements to downplay it and try to make his exit pleasant, in private they'd be celebrating. I expect it's a small minority of elected Republicans that really think Trump is great and like having him there. He's a total disaster, incompetent and embarrassing - not to mention a liability for them.
They are looking out for themselves by not attacking him openly. I think there would be dancing in their offices if Trump exited and Pence took over. Right now they can't get anything done. His administration is under multiple investigations, he is a security liability to his country and he's plain dumb as rocks and unable to keep his mouth shut.
The danger he poses to them is that he's shown a significant amount of the GOP base has become radicalized from all the propaganda and are now under his spell. Coming out against him openly will cost them their seat at the trough.
I have little doubt many of the leaks are from Republicans as much as they are from Democrats. I'll bet both sides of the aisle equally want him gone, but only Democrats can afford to be open about it.
He brings nothing to the table, no reasonable adult wants him where he his right now.