As far as I can tell, Air Canada has no specific limits for checked-in bags as long as you pay the $225 fee per bag for excess bags.
My question is if in practice I would be rejected at the airport if I show up with say 10 bags on a single ticket, for a flight from North American to South America. As it turns out, this may be the most economical way to bring some belongings as part of a move: shipping companies are quoting close to $600 per bag/box.