My guess is a more-likely outcome, if the GOP stays Trumpy post-Trump, is that a bunch of Reagan Republican types give up on Trump, just join the Democratic Party and get some policy concessions out of the Democrats.
Except the brand name is poisoned for their base. Forming a new party fixes that. The real problem is that they won't attract any big names from either side.
All the big name politicians on the right are the Trumpy nutjobs, and the big name politicians on the left are either too left-wing or they're entrenched leadership.
What exactly do you think CECOT is? Those people aren't awaiting trial.