I tend to use 50 mph for an average speed for planning from here in south Florida, it is roughly 5,000 miles or about 100 hours of driving time to Fairbanks. For me, that works out to be about 10 driving days. Seldom do I go up or back in those 10 days but have before. I know where I want to stop and spend time, so it generally takes about two to three weeks to get in that 100 hours of driving. From here to the Canadian border, I may make closer to 600 miles a day, then less the farther north I get.
When I go to the north country, that is where I want to spend my time, not sitting somewhere watching the grass try to grow. Some people like to only drive 3 or 4 hours a day, but it is going to take them a month, give or take, to get to Alaska. It you have no time restrainsts, that works for a few, but most of us, retired or not tend to only have so much time for the trip. Age and personal health play a big roll with some as a long day is too tiring for them. So how long to drive is a very personal matter for each of us to decide. I am an early riser and often on the road by 7 AM or earlier, so it is not hard for me to have covered 200 to 250 miles by lunch. If I want to stop and fish, I do or take a few photos. IMHO, a lot of the Alaska Hwy passing through the northern boreal forest, is a bit boring. What you see now, is what you saw yesterday and probably what you will see tomorrow. In the 20 something round trips I have made to/from Alaska, I have yet to find a reason to stop every couple of hours for the night. If, because of a persons age, one trip is all they will ever make, then they are going to want to see everything they can on this one trip. However, with many of us that are addicted to north country, we know/hope there will be future trips. At my current age, 72, I accept the fact that I only have a few more trips to take. I would like to get in 2 more round trips by RV, to give me a total of 15 rV round trips, a nice even number.
In the past, I have taken a month, one time, and another trip I made it from Anchorage to Houston Texas in 6 days. Neither of those are good choices for me except when those work the best.