Canadian models have full size spare. You can fit a full size wheel and tire in the US model but the cover may sit a bit higher and may necessitate removal of the storage compartment. I plan to get a full size spare when time comes to get new set of tires. Then I will "raise" the floor around the spare to match the new height of the spare cover.
As noted Cdn models get full size spares. The spare cover does sit 1/2 inch higher than the storage compartments on either side. The underside of the cover, with a big 'CAN" label on it is recessed to fit snugly over the tire. There is a further recess to accomodate the subwoofer cable which lays across the tire.
The cover measures 2ft 8.25 inches across and 2ft 7.5 inches front to back.
The maximum width of the compartment at the lip on which the cover sits is 2ft 6.75 inches in either direction, which allows the std GDY LS tire to pass through the opening with about 1 inch to spare.
I suspect the storage and tire compartment shell is the same on both sides of the border as is the bolt which secures the subwoofer, tire and body together. Key to a tidy fit is probably the ability to get the Cdn cover in the US
Sorry I can't post a pic but have yet to buy a digital camera! Perhaps another Cdn member (Jaak?) could post a picture of the tire inplace with the lid up.