Yes they certainly are available in Canada. Almost every local part store was able to order any Wix filter I wanted. None actually stocked any on their shelves. Call around to a few parts places to see if they can get some. Don't forget to check heavy truck places as well. Look up the part number you need on Wix's website to make the process much easier.
Napa Gold's and Carquest filters are supposedly identical to Wix filters. So, ask about these filters too. Locally they were more expensive than Wix, but it may be different in your area.