This is the first time we will be going to Disney and staying on a Disney property (only other time was a Make-A-Wish for our son). Are we able to charge all food/souiveniers to our room using our room key? If so, then I am thinking we won't need to have as much cash on hand. We leave Sunday, so just starting to take care of all the last minute details. I would prefer to just charge items and put them on the credit card already assigned to our room versus carrying case and cards around all day?