I think it would take another Geoffrey Howe moment for him to go. One of his more senior cabinet members needs to resign and make a knife-twisting statement from the back benches , just as Howe did. Whilst all his sheep still follow, we'll be stuck with him I fear.
Who could realistically replace him? Don't think there's anyone currently in a top job on the front bench I'd want anywhere near no10. The only name I could think of is Jeremy Hunt.