Rumor has it if you buy a GM in the USA and import it to Canada the dealers will not warranty. If you buy a used GM how old or how may miles or both would it have to have before the dealers would honor warranty?
Pretty sure that it has to be over 6 months old before you can bring into Canada and still have warranty. Mileage doesn't matter. By 6 months old it would have to be in service for 6 months.
It does need 12000km or be in service for more than 6 months. You can buy it with less mileage and time and import it, they just don't honour warranty until one of those criteria are met. I've done it twice now with no issue. If you do require warranty work before one of those two criteria are met you have to either wait or take it back into the states to have the work done.