Domoviye has a TL called Dark Canada or something of that sort.
Thanks for the publicity. It will be updated tomorrow night by the way.
My POD wouldn't actually work for this one, it involves the War of 1812.
The best way I can think of to get something like what you want, is to have a more belligerent US, without actually having a war.
Maybe make the Fenian Raids worse, and a harder push by US politicians and businessmen to take Ruperts Land. This would force early Canada to become more militarized.
Also at that time, politicians were incredibly corrupt and worked hand in hand with business to do almost everything. So the politicians and businessmen could form a capitalistic fascist society, that is based around the defense of the nation.
I'm not sure how you could get the Nazi racial ideas in there, but it could easily become Fascist in some form.