DeSantis would be eligible to run for Florida Governor again in 2032, as you can serve more than two terms, they just can't be consecutive after 8 years.
I imagine he will go private sector in 2027 tho he's clearly hoping Trump dies (or loses again) because he's taken the necessary steps to preserve himself for a 2028 Prez run. If Trump is gone from Earth, then RDS has a pretty good mantle for populist conservative champion. If Trump loses, he might be ignored by enough of the base for RDS to be a top contender. If Trump wins, not sure how RDS would be the next nominee.