In some respects, it would be lovely if he does stay on until the next GE and then has to formally give up 10 Downing Street to the Labour leader - having destroyed the Conservative Party through his hubris.
I would love it if he both lost his seat and destroyed the Tory Party in the process. Would he then resign whistling a happy tune as Cameron did, or would we see tears a la Thatcher/May, or just plain old boorish Boris bluster?
The day will come when he is gone because all political careers end in failure.