I went to Northwestern U for MS in CS right
after I landed in Canada. It seemed to me that
US schools, even the top ones, are less selective(although more competitive) than canadian schools. Because
I got rejected by both U of victoria and U of Toronto before I got I-20 from Northwestern.
during the years of studying and working in US, I realized that Northwestern is actually much more prestigious than any top canadian schools. So by going to the US alternative, you can bump up your career competitivity. Furthermore, you don't have to worry about your immigrant status because Immigration Canada will certainly have no problem issuing you return resident permit due to the fact that you are studying in US, which is considered for sure as an activity to improve your personal skills.