This may have changed recently. After reading your post I dowloaded a copy of the Northern New England AAA member benefits and they list an RV Plus coverage that seems to be the same as I have in CO. I also called and talked to a member services counselor and they said that the RV coverage is good through all US regional clubs. Didn't ask about Canada.
I asked AAA in Nevada about towable (travel trailer or fifth wheel) RV coverage. Answer- No. And no coverage for anything bigger than a one ton. CoachNet, no issue on size or type of RV.