If they would never vote for him either way then this opinion of tuners has no relevance to his odds.
25% of people who voted for Turmp now blame him for the Capitol attack. Some of those won't vote for Pence.
The MAGAs hate Pence even more, and won't vote for him.
There is no chance the GOP will risk putting forth a candidate who has both fringes against him, no matter how big the middle group is. Nikki Haley on the other end came out against Trump pretty early, but was still quiet enough the MAGAs don't know enough to hate her (albeit I personally think there are too many old conservative Republican voters who simply won't elect a woman)