You'll need four days for the round trip... IF you spend a couple of those days taking photos. While it isn't advisable for your first trip to the top, doing the round trip - Fairbanks>Deadhorse>Fairbanks in one day isn't all that difficult if you don't mind spending long hours in the saddle; I've done it several times. But Fairbanks to Deadhorse in one day, then back to Fairbanks the next - is a piece of cake for just about any Iron Butt rider. Actually, most any rider can do the one-way trip in a day without hurrying. Just get a good night's sleep in Fairbanks before heading north, then an early start the next morning. I like to leave around 6:00 AM, go out to Hilltop Truckstop for a good breakfast, then hit Coldfoot for lunch, and get into Deadhorse in time for supper. Another good night's rest, then head back south. You'll probably make better time on your southbound leg than you did going north, as that is the usual pattern.