"If an alternate leader will help bring Conservative MPs together in the national interest, I'll accept that."
Then whatever happens with Brexit, isn't on him!
There is a clear majority in Parliament against No-Deal, and that clear majority includes Tories.
So is the ability to say "I was PM for a few weeks" really worth risking a national disaster?
But if he can't... his sub needs to be off the bench and warming up around the pitch right now!