I'm pretty sure Alberta would be a GOP stronghold, and Republicans would also be favored in Manitoba and Saskatchewan.
The rest would obviously vote Democrat, though.
PEI might vote Republican, too. New Brunswick is anchored to the Democrats by its Francophone population, and Nova Scotia has Halifax keeping it in the Democratic column. Newfoundland could *maybe* vote for the right Republican but probably at least would lean Democratic because it is so poor and also surprisingly urban in population geography. But PEI has nothing really anchoring it to the Democratic Party. (It's also absurdly small compared to all other US states to the point of possibly creating a real crisis in representation; it might be forced to merge with New Brunswick or not become a state.)
Would merging PEI with Newfoundland be realistic? It would create two states of NB and NL having about 700k, around the average population of a congressional district, instead of one with 900k and one with 500k.