Where do you live, though? Is it a thing where you're surrounded by so many liberals that most of the few conservatives around are extra vocal just to be contrarian?
Aside from a few exceptions, almost every conservative I know in Texas would consider most of the Democrat candidates over Trump, but I don't have a lot of confidence that they'll vote for Bernie. I think you're underestimating the number of former Republicans who would cast a vote for a moderate Dem against Trump, but I also agree that the Bernie enthusiasm might outnumber it. I really have no idea.