Don't forget that once Preston Manning's Reform Rump took over the far Right from his Daddy's Social Credit, it was decades (and more than one name-change) before they disappeared into the un-Progressive Conservative Party of Canada. Not that the Refoooormers can't still be detected, for all that the t-shirts and bumper-stickers are the same. And it's kinda hard to see Hugh Segal and Brad Trost as belonging to the same party, but they do.
Maxime, may indeed re-enter the fold, but having left it so publicly, making his return look like a win will take some real political smarts. Not currently in evidence in the CPoC.
Meantime, with fringe-parties both left and right, this is Trudeau's prime chance to sell his preferred electoral reform: the Ranked Ballot, and live up to that hasty promise of 2015 being the last to use the outdated FPTP ballot that so mis-represents what people actually vote for.