May has been on borrowed time for almost two and a half years - ever week she seems to have only 48 hours to save her job and somehow scrapes through - so I'm not going to predict her demise this time because she seems to be good at two things (surviving in her job and keeping the Tories together) - though I wish she were good at other things too.
I think that the "rebels" have a major problem (no, not their ability to count up to forty eight, which makes me doubt their other skills) - the Tory party seem to dislike the people who betray the PM - e.g. Heseltine was a good candidate against Thatcher but they didn't like him because he was the one who drew the knife on her - so if Rees Mogg/ Johnson are seen to be scheming too much then I wouldn't be surprised if they are rejected in a vote in favour of someone who kept their powder dry (as Major did - with his conveniently timed Dentist appointment in 1990). The public might like Johnson as a figure of fun on HIGNFY but do MPs really trust him?
There's also the issue that a large part of the Brexit myth lies in being able to portray it as a "betrayal" - which is why Johnson/ Davis/ Raab/ Farage etc would rather snipe from the backbenches (or LBC studio) than actually take the difficult decisions as leaders - if they sit on their hands a bit longer then they can spread the myth that "Brexit would have been great, if only they'd given responsibility to people who actually believed in it", as if it were Fairies - that way you don't have to deal with any of the responsibility and nor do you have to accommodate the fact that the seventeen million people voting for change in 2016 were voting for lots of different types of change (some in favour of international free trade but some in favour of protectionism, some in favour of spending £350m/week on the NHS and some in favour of slashing public services, some in favour of turning the UK into Singapore, some in favour of turning the UK into Cuba...).
I wouldn't be surprised if they decide it's better to be seen to challenge May with a stalking horse but don't actually want to bring her down - at least that way they can keep pretending they'd have gotten away with (a perfect Brexit) if only it wasn't for that pesky meddlin' remainer!
A government of national unity wouldn't go amiss right now - not that any party considers the country above their own ambitions of power.
I'd be happy with that but, since we know that Corbyn won't share a platform with a Tory or be friends with one (though is perfectly happy sitting down with terrorists etc), any Labour MPs who join a "national unity" platform would be ostracised from their party - it'd be a convenient way for Corbyn to stay on the sidelines whilst expelling any "impure" MPs from the Labour party.