Acajacques Yes at this point it looks like nothing will stop the PQ (and perhaps a third referendum).
Though the next election is still over a year away which is forever in politics, and sometimes I wonder if the PQ might not suffer the same fate as the CPC and Pierre Poilievre did, and see their support collapse for reasons XYZ. The federal Liberals looked completely dead around Christmas last year and look at what happened. In the case of Quebec, the surprise would probably come from either the CAQ or the provincial Liberals. Right now it all seems almost impossible but especially these days, absolutely anything can happen in politics.
True, in theory, "anything can happen", and "it's not over till it's over", but in practice, no one rebounds from the sort of position the CAQ is in right now (did you pay attention to the Gallant Inquiry...? Actually you don't need to answer that 😉)
A few major differences between the LPC's Post-JT Rebound and the current CAQ:
1) The LPC is the Natural Governing Party; elections are theirs to lose, and in any "default" situation, they're the people's choice; conversely, the CAQ is the diametrical opposite, it's The Alternative, in fact so much so that it's almost stated in that party's charter, and unlike a Natural Governing Party, The Alternative is never shown any mercy when they're in power and they mess everything up. The LPC only had to find a Carney to get forgiven; the CAQ can't do that. It's Legault's personal vehicle and has never been anything else.
2) Poilievre is a politician with many real flaws, and a huge chunk of the electorate always found him toxic, so even when he had a great window of opportunity, his toxicity prevented him from fully taking advantage of it. Conversely, PSPP is almost the anti-Poilievre -- liked and respected by even those who don't want to vote for him. Plenty of voters who'd vote "No" in a third referendum, would gladly vote to elect PSPP as PM of Quebec.
So, in summary,
1) The CAQ isn't the LPC;
2) PSPP isn't Poilievre;
3) There's no Carney available;
4) The incumbent party's problems and the resulting unpopularity, aren't anywhere near as easy to fix as just getting rid of one person (Justin Trudeau).
Edited to add: Just compare the rebuke Justin Trudeau got in a friendly stronghold (Toronto St. Paul's) to the rebuke François Legault got in a friendly stronghold (Arthabaska).