United has changed the flight times so that we will arrive in Kona an hour plus later on Thanksgiving week. I have a minivan at a low rate due to way advance booking, and if I amend the time of pickup on the reservation I think I will lose my rate. We will pick up over an hour after the scheduled time. Is this going to endanger the whole reservation? If I call from departure airport that day, is that the best way to handle this? Thanks.