They are also having to grapple with the fact that undoing Brexit slowly is very very hard to oppose in a popular sense. In a way, history (after I am dead) may well show that the cliff edge Brexit delivered by Boris was the best way to ensure rejoining happened. Because we can now see people having to oppose each strand of what EU membership was, and find little to object in each.
Also the Boris Brexit rather cur off the oxygen for the future. If the UK had remained in the CU and/or the SM, then it would have provided fuel for continued "we have to leave" political pressure (that may well have saved the Tories).
As we move on from the emotions and just read the logic, it was inevitable that the plan delivered by the party and man without a plan should start to unravel within months of the Tories disappearing.
The only thing Remainers have to do is repeat the mantra "Brexit is done". Only be careful - it really upsets some (as any posters who have persisted in the obsolete "Brexit" forum will know).
Merry Christmas one and all !!!