I must admit that I've kinda sailed through the pre-WWII writing, but at this point it starts to make impacts on others (as people have pointed out) and I'm not quite sure where to go with that just yet.
For starters, I gotta think about an idea that has interested me for a long time - Churchill's idea of having France join the UK as it was falling to have portions of the French armed forces evacuate to Britain and thus live to fight another day, and then have the Union remain alive after the war. This is more likely with a successful Canada that has greater achievements for its French and Native populations, but still a tall order. And people are right about the effects of the Civil Rights Movement, and Canada being that way also could have big impacts on plans for Caribbean territories, too. I'm not sure quite yet where to go on that all, having to research it all.