The problem is I'm discussing 2 different issues with 2 different people. I'm not saying that is what you said. I'm saying I'm in the exact situation you suggest strategically voting for and mostly arguing for that with the first person who said "but it'll make a 2 party system". That said, I think arguing that the PCs aren't as strong as they seem in this era of right wing resurgence literally everywhere in the world is asking for tragedy.

My stance is unless the PCs have zero chance in hell of winning a riding the voters should prioritize ensuring they lose. Protesting or lobbying for change towards Approval Voting can come after the election (or, ideally, pushed to the forefront as an election hot-button issue). Once that succeeds Party survival will be a non-issue.