Johnson gives the Tories a better chance but... the route back for him is littered with obstacles, the investigation, the fact his own party will look like proper tits for pushing him out then bringing him back, the fact that should he return, he's then got to deal with the fact his own party has created more difficult economic choices and he doesn't like making those choices and so on.
I suspect that his fans will rejoice and many will recoil. The interesting question is whether the floating voters recoil or not. My suspicion is that there's a good number of people who voted 'Boris' as opposed to voting 'Tory' and thus, those people are very, very important to the Tory party (and they're also why the Tories are split down the middle because their priorities are not traditional Tory priorities) - same as Labour struggles to reconcile the 'old miner' types and the 'woke student' types as there's a dissonance) and as they've placed their vote because they want him, they're unlikely to vote for Mordaunt or Sunak or whoever.
Basically, Boris transcends the Tory party with his ability to talk off the cuff and whilst that's a limited ability that is probably not of enormous use in terms of doing 95% of the job of PM it's also a rare quality. He's a flair politician so to speak and they are in short supply. He's kind of the opposite of John Major who had all the aptitude and none of the flair.
I do wonder if him returning will split the party even more though. Johnson will bring both chaos and stability in that with Johnson, the chaos is all part of the act and seen as chaos is apparently the new normal, then there's a certain twisted logic in wanting Johnson there at the heart of it as he thrives in chaos (by design)