Can't speak for Montreal ... I know all the sporting stores have them here. I purchased mine at Athlete's World. They also have them in some Shoe Companys, and Mountain Coast sporting stores.
Although cute for a trip, I won't buy Mickey crocs next time for my DDs. They want to wear Jibbitz, and they just don't fit well at all. They don't work with adult Mickey shoes at all, but the kids ones kind of hold them. So far, we've lost 6 out of 10 purchased... good thing I bought them 4 for $5.