I concur with Steve.
A 15 year old or older bike is a cake walk. A newer bike on Transport Canada's approved vehicle list is also doable. A 15 year old or new bike not on the list is virtually impossible.
There is one very sketchy process, it apparently worked to import Big Dog and some of the choppers build in the states during the Orange County Choppers craze. Import to Alberta. Apparently they don't worry too much about red tape. I don't know the process; I just know anecdotally that's how they got in the country.
There is also the Chinese import scam. Swear false statutory declarations that the Triumph Bobber is actually a 1968 Bonneville. I know this works, but won't tell you how I know.
Peace & Grease, Dennis