[Rick Lee]

You'll be fine. Dulles is not bad at all. Grab your bags, take them right upstairs for rebooking, go through security, walk on the nearest bus to your terminal and you're all set. Those buses depart just about every minute. Once in the departure terminal, it's never very crowded there. I usually prefer to take the underground walkway to the terminals, but they are misleadingly long. Don't do it unless you have plenty of time and really want to stretch your legs.