Here's a thread from a
Canadian with a nook on buying from the B&N store. There is a certain amount of hoop-jumping involved.
Frankly, if all you want is a simple reader, then the Kobo sounds good enough for that, especially if you're not planning to use the nook's wi-fi or other special features.
And you can get support for it in Canada.
Perhaps the best thing is to try both out during your weekend trip if you can, and see if there's anything in particular about each that really appeals to or bothers you.