I am not too familiar with the KKK in the US although I know about their actions and beliefs in the Canadian context, particularly Québec. Any American knowledgeable about the KKK in the United States is free to add or correct anything I say when mentionning the American KKK. I know the KKK in Canada was along the lines of the second KKK in the United States but I am not sure what that would mean more precisely.

The KKK in Canada had a wildly different setting than in the US though. It for sure was racist and believed in ideals of racial purity, but the canadian context was particular with its French/English divide and the French usually being catholic, a lot of the KKK efforts in Canada were targeting the French. The American KKK had no love for Catholics but demographic reality of the US being what it is, a lot more of the work was centered around fighting racialised folks.

In Canada, the content of the conspirations of the KKK were often centered around Québec or the French/Catholics trying to implement their ideology, religion or language in the public sphere. There were even claims that Québec was conspirating to make Saskatchwan the second french province. Its influence was mostly in Saskatchwan with the rallying point of counter-balancing the Liberal party who had a strong core of French-speaking supporters. Their influence was limited although visible but their relative success was due to them capitalising on linguistic issues. After showing up in in the early to mid 1920s, the American organisers in 1927 stole the membership money and within less than a decade, the Klan in Canada was once again mostly irrelevant. There were members as well as attempts to revive it (as recently as the 60 or 70s, where they disavowed the racist ideals of the US Klan) but none of it were particularly successful. So in short, there are few actions outside Saskatchewan that can be attributed to the KKK. I know of a dam being blown up in Ontario that actually caused people to dislike the KKK and a few suspicious fires of churches, but that is about it.

So what about Montréal? Vancouver and Montréal were the first cities where the KKK tried to recruit. A major pitfall of the Klan was simply the fact that Canadians did not care about blacks all that much. Do not misread me: Canadian society was racist and had many racists. But nothing like the civil war or the history of slavery of the US. Most political turmoil in Canada was, as I made clear, centered around religion or language, and the Klan had to adapt. Canadians were not open-minded land of openness and apologise-ness. Its tensions were simply different and there was moreso an indifference towards blacks than an openness.

In Montréal, it is where the Klan realised that its brand of racism wouldn't work too well. THe majority (French) was catholic and for the English to be into it, they would do things like promote more fiercely British roots, Union Jack photo ops, the protestant aspects, and fight what they saw as the incursion of French in their daily lives. Very little of note about the Klan in Montréal...at this point.

In the Montréal of the 90s, there was however a resurgence of right-wing extremism. I am aware that the Klan capitalised on the Oka crisis and had actives members distributing pamphlets. They were part of a more widely increase in right-wing extremism in the province. It was a bit of a mixed-bag; nationalism was back then moreso associated with the left and many of those groups as such had limited roots in Québec nationalism. Many were targeting blacks, jews, and LGBT+ with little ideological motives that would associate them to mainstream nationalist ideas. They were nonetheless violent, with some people even murdered. It was nonetheless fairly contained with my knowledge showing intense activities for a few years before dying down. Contrary to the earlier "Canadian" Klan, the Britishness of Canada was less emphasised and the focus became moreso against minorities like Jews, Blacks, and LGBT+ folks.

At the moment, there is a resurgence of right-wing extremism in Québec, with a very different ideological flavour but that would fall within the 20 years rule.

A good book on the matter, most of which I got my info from, is by a scholar at UBC called Pistula whose book is titled "Keeping Canada British". It goes in depth on the KKK in Canada but more widely why it took hold in Saskatchewan and less so in Québec, Ontario, and BC. Don't hesitate if you have any questions (French, English or Portuguese if you are more comfortable!)