WE slowed down after I retired a few years ago, which gave us more time during the summer to travel. We had no problems slowing down and taking our time with the Blue Ridge, which I suspect is something like the Natchez Trace. But only you know yourself well enough to say how you will do.
We still do a moderate push when we are headed for the west each year to get us by the boring to us part of the trip. On I-10 things don't get interesting until San Antonio. And going up US 287 isn't all that interesting until you get closer to `Amarillo where there are some interesting state parks. We tend to do 400-450 mile days for the first two to three days of our trips. But we've been doing this since the mid-1980's when we did 600 mile days and once 1200 miles in 30 hours. And then there was the North Florida to Yosemite run in 4 days...heh the bad old days.
We took the north route for us a couple years ago and took our time by driving on Iowa secondary roads and we have done the same in Texas, finding a very nice city park in Mason TX. In Iowa we found the awful city park in Atlantic...heh. In Louisiana we found that I-10 isn't the only horrible road surface in the state all the secondary roads were bad to worse. So you never know what you'll find only that it will be interesting.
I would suggest that you add Mammoth Caves to your itinerary if you haven't been there. You can spend a couple of days there and there is a lot of history in those caves.
We tend to now days to do a base camp for a week and thoroughly explore the surrounding 100 miles or so. Then move the base camp and repeat. We call it exploring a state. Northern Utah and Idaho are on our list for this summer.