TN worker and student with fellowship

[notoriouspg]

Hello,

I'm working in US on a TN visa, and my fiancee is staying with me as a visitor until our wedding this summer in Canada, after which she'll apply for TD status. Before our move here together in January, we'd been living together continuously in Canada for 19 months (we've never filed taxes jointly). She is a full-time PhD student at a Cdn university, but is carrying on her research here. She has a Cdn gov't fellowship (CGS) which is completely tax-free in Canada.

My main question is what we should do next year when we file taxes for 2010. If we file as a married couple, can we be considered non-residents of Canada by CRA, in spite of my fiancee's enrollment in a Cdn university? We have no residence in Canada, and I am in the process of severing other ties, like driver's licence, banking stuff... but I'd like to keep a basic bank account in Canada, and my fiancee would like to keep hers for the purpose of receiving her scholarship funding. She will also have to keep her Cdn health card until we're married since she only has emergency travel medical insurance in the US for now (will be covered by my employer post wedding).

Also: even if Canada considers us non-residents, will her scholarship $ be taxable by IRS? (although how could they find out about it?...)

I feel like some of this confusion can be avoided if we never file as a couple in Canada (including for 2009), so that CRA always sees us as separate individuals (she can file with her parents' address). Technically this is probably illegal though...

Thanks for any advice!