I am going venture an opinion that a truck camper is NOT an RV. It is not a vehicle at all, it is something you put in the back of a pickup truck to make it more comfortable to sleep in. It is an attachment to convert a common pickup truck into an RV. I have a cap on my truck to keep my camping gear secure and dry. If I threw in a sleeping bag, a coleman stove and a portapotti, I would have all the amenities you will have in your new camper, just not the deluxe version. It doesn't have to be registered in any province or state that I know of. It will of course have to be within the capabilities of the truck under it.
Long story short: you are not importing a vehicle, you just have something new in the back of your truck. It could be a camper or a dishwasher or a piano or an aluminum boat.
Stu