It all depends on how much time we have for the entire trip or how fast we "really" need to get there. On average, for the last 10 years or so, it's about 6 hours on the road a day, however far that just happens to be depending upon where the travels take us.
One thing we learned a LONG time ago: it's just absolutely no fun, no fun at all, to drive hours and hours and hours to arrive at the destination and then be so beat-out and tired you really can't enjoy the time AT the destination, because all you want to do is sleep and the entire entire time there is nothing but a blurr. Fatigue is nasty. And the older you get, the worse it gets. So the drive should NOT wear you out... or those with you, so you feel good and enjoy the destination.
For us, we always plan on lots of stops now, we plan on things to see and do along the journey. We don't mind shorter driving times to experience more road side attractions or surprises. We plan on some of these, and sometimes, just they happen very unexpected. And believe it or not, it's the unexpected stops and events that we always seem to remember the most and laugh at the most. The planned activities somehow seem to get forgotten in time.
For example, here's a few photos of the unexpected that left quite an impact! But looking back, I have no clue what we were actually doing: