I'm from Alabama, but have lived in Georgia much of my life. Long story short, born in Birmingham, but spent almost all my youth in Atlanta. I was a legacy at Alabama and went for school, then immediately back to Atlanta. Basically, of my 44 years, about 7 were in Alabama, the rest here.
I do not know Kemp's mind, and I have not ever met him. I do however, know several people in his orbit in the real estate world (including one that is a good friend of his and was a fraternity brother at UGA). Like many Republicans, this guy just assumes that everyone around him is also a Republican and he is a braggart so he boasts of his conversations because A. He think's he's cool (he's not) B. He thinks it makes him sound plugged in (he isn't). To answer your question, I know him and several people around him were pushing for him to swoop in late for POTUS once the early primary clowns were out and it started to appear that Trump was finished. I did find this plausible, and if there had been intent, I think the court delays stopped that.
The timing on the Senate is interesting given Ossoff's term being due next, which coincides with the next Presidential. He can run for one or the other, what's his ambition level? He may well be the standard bearer for the anti Trump Republicans and an example of success against their stupidity. Regrettably, I don't think he'll just fade away. If I had to put money on it, I'd say Senate, but I wouldn't rule out a POTUS run.