I think Boris will rapidly lose interest in being the MP of Uxbridge about twenty seconds after they take off his shiny 'I'm the PM' badge. I suspect he's got zero interest in returning to the back benches.... which to be fair to her, Theresa May did with good grace and has an excellent reputation as a diligent MP. Johnson is cut from the same cloth as Cameron, it'll be book after book ghost-written in the shed (Cameron may write his own stuff, Johnson almost certainly doesn't)

If anyone can engineer an extremely rare condition on which he's allowed to inherit the Baronetcy of Uxbridge, it's Boris. I doubt he's getting into the Upper House by any other means, he's about as popular as a fart in a spacesuit in the Tory party.