If New Brunswick became an American state ...

[Oryxslayer]

All the Canadian provinces except Maaaaybe Alberta would be solid Democrat.

HAHAHAHA, No.

BC is roughly an extension of Washington, so its a safe D state. Alberta/Saskatchewan/Northwest Territories are similar economically and demographically to the plains, or northern Rockies, safe GOP. Yukon - another Alaska. Nunavut is majority native, so thats safe Dem. Manitoba is similar in pop distribution and economically to Minnesota, so we can probably call it a swing state. Ontario is another New York/Illinois so safe Dem, maybe likely at the worst. The Ontario PC's have appeal to demographics that the GOP could never match in places like Peel and Scarborough. These minority communities would be lock-step dem rather then swing like in the Canadian system. New Brunswick is just ME-02 extended, so swing GOP. The other maritimes all should behave like New England, but I could see Nova Scotia voting GOP. Quebec is unique and defies traditional demographic weights.

These are all generalizations, but I could go deeper into the weeds if needed.

[Oryxslayer]

Not going to try to parse out what might happen with third parties (with the exception of Quebec - that's probably obvious enough of a rogue state to sustain a legitimate third party), but maybe something like this:

I think the NW territories, being close to tied between (US Left) Aboriginals and (US Right) migratory extraction workers probably makes this a swing region, similar to Alaska if we drop the greater Anchorage metro and her very red suburbs. Yukon is majority northern resource extraction workers, so is probably as Atlas Blue as Fairbanks. That said, both these regions, in addition to Nunuvut, would be still us territories because of their tiny populations, unless all three ended up merged together.

The fate of the Immediate Maritime provinces, New Brunswick and Nova Scotia, will depend upon whether you think they behave more like ME and NH as a whole, or like ME-02. As I said earlier, I think NB would be more like the CD, whereas NS more like the states.