It depends on what restaurants the reservations are for. You should be fine, unless you had to leave a credit card number for a deposit for payment in full. For places like the California Grill or Akershus that have you hold the reservation with a credit card you will be charged a fee for each person that is a no show. For someplace that makes you pay in full in advance (like a meal at the castle) you will forfit the full per person amount.