I think so. I can purchase off the US site with my Canadian credit card but I need to ship it to a US warehouse and pick it up. Costco.com doesn't ship to US PO boxes that forwards packages to the Canada.
I check the US and Canadian sites since the inventory is different.
I was just wondering myself if I could purchase from a Canadian warehouse, and then travel to pick it up. Do you have any issues crossing back over with your purchase?