I didn't really investigate, to be honest. Usually, most offers are not for Canadians. I tried to order an advent calendar from Macy's for my sister, who is in the US the other day. It went fine until they asked for my credit card. They would not accept my Canadian credit card. I tried Paypal. They would not take Canadian Paypal. It seems so strange to me because Canada is not so distant from the United States. Amazon US, at least, is happy to take our money.
I think this is an area where crypto may really improve the situation (she said optimistically). If I were paying with crypto, maybe a store or website would not worry so much about whether it was Canadian crypto or American crypto. I guess we shall see? I am very curious to see how adoption will take shape.