As but two examples, your analysis completely ignores the decided impact of - not only post-WWII - but all 20th century immigration. Plus, aside from a primarily non-British influx having more than left its mark, what of the somewhere in the vicinity of 100,000 generally well educated and well connected U.S. draft dodgers and military deserters who arrived here in the 60's and early 70's?
Like socialist cadres anywhere, they've since wormed their way into virtually every culturally and politically sensitive nook and cranny in the nation. Next time you hear especially virulent anti-Americanism coming from up this way, if you follow it back to the source, odds are you'll find either one these vermin or someone they've helped brainwash within our public schools and universities.
While this isn't to say there hasn't been historic rivalry between the two nations, actions and attitudes related to World Wars I & II and Korea attest that it was principally of a 'between brothers' nature prior to the Vietnam-era arrival of the literal dregs of American society.
On a personal basis, I find your 'High Tory' theorizations and generalizations with respect to Canadian Conservatives especially offensive.
My family, aside from having paid its social and military dues over the same time-frame, can document its Conservative ties going back almost a century. Yet, my paternal grandmother chose to receive her nursing education stateside and was decorated for her WWI service in America's Harvard Surgical Unit. Further, both my wife and I are proud to have cousins who served in Vietnam - including one listed on the 'Black Wall' in Washington DC.
In short, here's the authentic face of "TRUE BLUE" Canadian Conservativism with respect to America:
BTW, I know, I was there...
... in downtown Toronto, Ontario.