Okay, I think you left that part out of the OP and we all made some assumptions. I didn't realize we were talking about cancelling one of two reservations, but rather thought we were talking about cancelling everyone's reservation. I figure that was part of
@BillPA's point about the son being the owner. If the reservation is in the son's name and he's deployed and can't go, I bet they'll work with you to cancel the one room. Or, you could purchase
trip insurance.