Not sure of the bank(s) that issue the credit cards in Canada. But even in the USA especially chase cards it is always a good idea to call the credit card before you travel and let them know you will be making charges in X state and or country. If you visit Florida every year with the same card after the first time you should be ok.
As a last resort if nothing else works, although I am sure Mickey can get you $$$ diapers, if you go to DS walk across the bridge by on a upon a toy to hotel plaza- going right will bring you near the Hilton not sure of the other side? Follow the path past all the hotels around a mile maybe a little longer there are stores across the street when you get to the end.