Without the (limited) checks and balances of Parliament, God knows what evil he will bring upon Canaduh, by fiat.
Polievre can argue before the Governor General, that proroguing Parliament, just to hold a leadership convention is un-Parliamentary, but, since the GGis a political appointee, chances are, this won't succeed, so we are stuck with Castreau as Crime Minister,in a prorogued Parliament,until possibly May and no election until July, possibly.
His 'resignation' is not what it appears to be.
Here is a YouTube video by Michele Rempel Garner, Conservative MP for Calgary Nose Hill. https://www.youtube.com/watch?v=GKUPVdROxL4
While he can do limited damage with Orders-in-Council, those can and will be revoked by the Tories once they are in office.
With a Leadership election, Trudeau becomes a lame duck and the Leadership candidates are going to run far away from him, because he is so toxic with the electorate. All focus is going to be on the Leadership election.
However this will not fix the fundamental problems with the Liberal Government and they are still going to lose the next election. However, they might avoid total catastrophe.