I'm taking the path as suggested by cyberwulf, and now doing a masters in Canada at one of the top 4. My two cents on why below, you may find it helpful:
I also had a single NSERC RA, and similar grades from a decent but not top 4 in Canada. I got into all of the Masters programs you listed early in the admissions cycle, and was competitive for the CGS scholarship at each so I think you will be fine getting into those. I didn't send any applications to PhD's since I thought even if I had a chance, I could only increase that chance by doing the Master's first. I don't see the two years as wasted, it gives me more of an idea of the graduate research experience in math/stats (I was a late bloomer, first research right before 4th year), and also a way out to industry if I'm not interested, since most statistician jobs require a Masters here in Canada.