Well, the war in Canada certainly was brutal. But unless America actively prevents Toronto and Ottawa from rebuilding after the fires, it doesn't seem brutal enough to prevent Canada's OTL major cities from attaining high populations.

Well, looking forwards to seeing how the integration of Canada goes, and how the Canadians react when they realize the 'yankee devils' are in fact not going to unleash hordes of 'negro rape gangs' (or whatever they're scared of) on them.
You won't even keep the prairie provinces?

Also, I messed up before--Nunavut, Yukon, Ontario, and Nova Scotia will be the only states to retain their Canadian names. Every other state will have a new name. Also I'll be redrawing Canadian subdivisions for their entry into America, so don't get too attached to anything so far...