I'm not as familiar with Canadian politics. How likely is something like this to happen?
the current Liberal majority is safely in place until October 2019.
The Conservative Party is having a Leadership race with a wide variety of candidates ranging from a socially Liberal Conservative, some moderate conservatives, some social conservatives, one free-market Libertarian and one White nationalist nut job.
but the seeds of hate can quickly spread like a wildfire on social media that could complicate things but 2019 is was too far off.
Trump has lots of time to completely fail before Oct 2019
the other thing is that Canada is a very regional country and its major urban centers carry more weight than they do in the US, a nut job would not of consensus across all Provinces
*in addition. Canada has a large Ukrainian-Canadian constituency in the prairies and they lean Conservative. Formerly, Harper was staunchly anti-Russia and made a big deal about Ukraine's sovereignty during the Crimea episode. So, if a future Conservative leader decides to cozy up to Russia, they lose their Ukrainian-Canadian base. + the Arctic is a big deal, so it is anti-Canadian to have a Pro-Russian as leader of a party