That's the candidate's problem and responsibility.
There is a line of thought floating around that the RNC wants to lose, not just because it shares cronyism with DEMs (although that's at rock bottom), but also to teach the conservatives who use Trump as a vehicle, a lesson that won't be forgotten for a generation. The Goldwater example is brought up. "Run a Limbaugh-conservative, got your ass kicked" sort of event. I mention that just as a sort of "beware snakes in the grass," The party is not Trump's ally in fact, but you can bet it will put on a good act.
I believe that there are actually quite a few GOPe types that think exactly that.