There are many places in either the US or Canada. It depends on just what you are looking for...i.e. Yacht Club or storage>
If you are in Toronto, I would put it indoors at outer harbour marina. With a 50 ft cruiser, you are somewhat limited to who can haul out. Other options are Ship Shape marine at the bottom of the Welland Canal. They have a big enough lift. However, you can probably get a better deal if you were to cross to the states, maybe youngstown or Rochester.