I really don't think you'll save much on most souvenirs in Canada compared to the United States. Personally, I think the only thing that is a noticeably cheaper in Canada is some of the local seafood. I remember when you could get live lobsters from supermarkets for about C$5.40/lb.

If you're looking for unique gifts, I guess some take-home Tim Hortons coffee mix is pretty Canadian? Maybe some ice wine as well?

I guess maple syrup is an okay deal in Quebec, although you can also easily find it south of the border in Vermont as well. With the low Canadian Dollar, some consumer goods have become occasionally cheaper than in the United States such as some electronics as well as clothing (e.g., Tommy Hilfiger). When the Canadian Dollar rapidly nosedived to 1.47 CAD/USD, I believe some items such as the Xbox One were 10-15% cheaper than in the US even taking into account Canada's higher sales tax. Since prices have adjusted, you won't really be saving much as the sales tax is 13% in Ontario and 15% in Quebec compared to no more than 10% in any US state.