So we are thinking of canceling a credit card because of its high annual fee. I just realized it is the card I used to guarantee a dining reservation in Sept. If we cancel the card, will we lose the reservation? Should I call and put another card as a guarantee? We don't want to do anything that would cause us to lose the reservation. Also, we made the dining reservation for 10 people in case our son and daughter could join us but it is looking like they will not be able to join us. Do we need to call to modify the number of people when we know for certain that they cannot join us? Thanks in advance for your answers!