True - but what could also be a possibility is if the Massachusetts/New Brunswick border (Maine most likely remaining a region of Massachusetts in TTL, unless stated otherwise) could be along new lines. The current border between Maine and New Brunswick, based on Webster-Ashburton in the 1840s of OTL (as is the Maine/Québec border), could be changed from the Saint John River to, say, the Penobscot and Allagash Rivers. (That's what I'm using for a TL I'm working on).
True, but isn't that how all maps start out as?
Well, since the PMs may be different in TTL, I could see someone going for three big provinces in what are now Alberta and Saskatchewan.
Hmm, interesting idea - or, in case of a Mexico that retains its northern territories in TTL, minus Louisiana, why not go straight for the Mexican border? I know it will be giving stuff away regarding the long-awaited Part II of my TL,
Kunado el Rey Nimrod (for which virtually most of what you've done so far would fit perfectly in - so again I ask, would you mind if I used your ideas?), but in my TL Mexico is pretty much a Brazil analogue, partly because it retained the monarchy longer than in OTL (since basically only the competent side of the Spanish royal family are ruling Mexico) - if Mexico in my TL retains its northern territories, it could be possible for a definitive Mexico-Canada border that would allow BC to retain most, if not all, of the Oregon Country.
Makes sense.
Well, I just like the idea of Northern Ontario being separate from Southern and Eastern Ontario, but if one can hold Ontario's boundary at the provisional expansion, that would be fine.
A man can dream, can't he?

A place in the sun under Canadian control sure sounds very attractive.
Understandable.
Looks good so far - with the possibility of some adjustments, but would be until much later. Oh, and why not have Alaska as part of Canada? It's a cliché, yes, but that would be cool to see.