Having made trips from Hattiesburg, MS to Alaska 3 of the past 4 years, I cannot emphasize enough that to really enjoy the trip, do not think in terms of how much time it will take to get from point A to point B. I know that people who have a limited amount of time might need to do this, but if you have "unlimited" time, try to just go with the flow and see, do, stop wherever your interest leads you. On each of our trips, the only campground reservations that we made were in Denali and in Seward for the July 4th week. Otherwise, we just drove however far we wanted with a vague idea of when we would arrive and how long we would stay. An example being Valdez where we originally thought we would stay 3 nights and ended up staying 7.