You need to sign up for their red card and then use it when you make your purchase to get 5% off. The RBC MasterCard from the Cdn site will work in the US. Stores to get the 5% off but the Cdn debit red card will not. The other option is to sign up for the US credit card red card - Cdns can do this as an option as well. Either way, you'll be paying 2.5% in foreign exchange fees, so the real savings is only 2.5% at par.
The Cdn stores do not sell Disney gift cards as far as I can tell.
Now if you are able to get your hands on one of the 20% off storewide coupons that Target is releasing on Black Friday to be used the following week, that would make it worthwhile.