I recently shipped my household of stuff in a container from South Africa to The Netherlands. I know that the container was X-rayed with a big-industrial freight scanner, because I had to pay the shipper a pile of cash to move the container to the scanning station and back at Customs in Rotterdam. As a precaution, I did not ship most of my film, and brought it along in my hand luggage, and I assumed that the leftover few bits of film I'd left in film holders in the container would be a dead loss.
However, I found there was a half-shot roll of Tri-X still sitting in my F4. What did I have to lose? I shot the rest of the roll and processed it. The film is pristine and beautiful. There is no indication of any effect whatsoever on the images.
If a big, industrial container scanner in one of the world's busiest ports didn't damage my film, it's very, very unlikely to have any worse a problem moving film between the US and Canada. (Oh yes -- and I also used to pretty frequently order film from the US or Germany when I was in South Africa -- never an issue)