Apple did a stealth launch of the iPad Mini overnight at 0300ET and the Apple,ca online reservation system is now available to serve you (yes... even in Canada). It lists the locations that have inventory and the list seems to change periodically so check it out to see if your local Apple store has any available.

Ive checked a couple of times and even touched base with American contacts and it seems the only models available immediately are the WIFI versions in 16/32GB versions.

At 0730ET all locations were in Ontario and Quebec but this may change throughout the day.