It's an interesting dilemma for them, squeezed between Farage monopolising their basest, most feral instincts on one side, and what is the current closest analogue of old school Tory One Nationism actually in government.
However I'm still inclined to think that a (still distant) general election won't be the overwhelming Reform landslide many expect, or indeed wish for. Most people aren't particularly politically engaged, and the idea that for those, politics is "what's on in the background when they're making a cup of tea" implies that there may not be any great public hunger for more 'change', or wish to subvert the status quo.
What the Tories might do (beyond the necessity of defenestrating Mad Badenoch) will be interesting to see, but I think Reform's best chance of making significant gains will likely be a similar level of apathy that led to the government we currently have, where 'traditional' Tory voters clearly just stayed in bed.
And nearer the event, if they're still both targeting the same Carling-swilling, binburning demographic, some sort of Tory/Reform alliance wouldn't surprise me in the slightest.