Whilst there's a lot of fairly loyal Tories out there, the same could have been said about Labour and the Lib Dems. In the last decade they've all done stuff to significantly upset those other than their very core voters. Which I believe means that there's likely to be a lot of people who find themselves alienated from who they thought that they should vote for.
We've seen this in the Southwest going from yellow/orange to blue and likewise the former red wall seats going red to blue.
Whilst there's likely to still be anger over tuition fees for the Lib Dems, I suspect that this has reduced recently and so they have the potential to draw a lot of conservative voters to them due to the current upset with the Tories.
However I suspect that is there was an alternative fairly central party, maybe slightly left leaning, without the current baggage of the current political parties then they could do fairly well.
Whilst the Green Party could fit that description, and with a significant growing support for all things environmental, I'm not sure that they are likely to have the mass appeal yet. Mostly due to them only having one MP, so they would currently be seen as a bit of a protest vote. Of course the Lib Dems could have a similar argument placed at their door, however at least with them they have in the recent past had a half decent number of MP's.
The May local elections, where people are much more likely to "risk" voting for someone else are likely to be interesting. In that there'll be a lot of people wishing to show Boris their upset at the Parties (although there's been a level of upset about various things which have been kept back, as we were in a Pandemic, which is making the current anger worse).
For instance the issues over PPE contacts, the redecoration of the PM's flat and how that was paid for, the rolling back of the £20/week, the miss handling of Barnard Castle (which many will now put down to that none at the top seeing how toxic that was, as the perception is that those with money were all doing it - for example a lot of second homes in Cornwall were in use) and so on; I'm sure that there's plenty of other things which others could add to that list.
Boris' "I'm sorry you feel that way, "I'm sorry I was caught", or whatever other non apology he's said is likely to have only added to that upset. If he does what many see as the right thing once the Sue Grey report is produced, then the Tories could have a chance at staying in power. The problem is, what does that right thing to do look like?
Many want him out, however if that's all that happens then there's still going to be the issue of the thinking "yes he's gone, but what about others and the civil servants who must have been involved?".
Late in 2020, when working in an office was allowed, we had a work social with drinks and snacks. However we'd all gone home after work and had that "party" using online meeting software. I suspect that wasn't unique, and so to then see number 10 having an in person party is likely to be more upsetting than number 10 can understand.
Likewise at the time of the parties, my wife's work (due to being science based involving lab work, so there were often everyone fora meeting in work buildings) had all their meetings online, even when it was just a few of them. They would all have to find their own office space and then have a meeting.
Again not likely to be unique, that's before you consider the impact on children, people's mental health (personally both being on furlough and WFH for prolonged periods of time have caused me issues, which I've dealt with as they were fairly low level), or the many other sacrifices people have made at the request of the government. To then see that they've made far fewer and then not confess when they've had chance to (compare number 10 to the department for education, who just apologised when this all started out), then that's going going to be hard for them to resolve.