Desantis is absolutely un-electable with Trump running as a third party, I don't care what you do. The democrats could run a road kill 'Possum that is bloated with maggots, and they would get 45% of the vote, Trump would get 20-25% and that leaves DeSantis with 30-35%. The only reason Trump won in 2016 is that so many people hated Hillary. Trump lost in 2020 because more republicans hated him more than they feared a Biden administration. As bad as Biden is, they still hate Trump more than they fear another democratic administration, even if it means socialism as the law of the land. This is an undeniable fact, as sad as it is.
There are two possible scenarios that will stop the democrats in 2024, first is the possibility of a Trump/DeSantis ticket where the trump haters can see light at the end of the tunnel and DeSantis lurking for a run in 2028. This would require the Trump haters to hold their nose and vote for Trump one time to head off eminent disaster. Second, is that the Trump haters see the evil Biden has done and get behind Trump from the start. Unfortunately, neither of these scenarios will happen because the Trump haters live in a fairy tale world.