We are destination people and we travel hard to and from said destination. I have mentioned in other posts that having a "Jumping off point" helps us quite a bit. My hours are 6-2:30 and my wife is a high school teacher so she works the typical 7-3:30 shift. The difference between our commutes puts us both home at exactly the same time most days. (The myth that teacher only work 6 hours is annoying by the way, thanks to a teacher most people can do the math and 7-3:30 is 8.5 hours.)
I try to get home early so we can leave by 4 on Friday evening. That day is a reasonably short drive, but I still try to put 200 miles between me an home. Typically with a meal break at around 100 miles. As long as the batteries are fresh in my sons toys we can power into the night with little issue. I call that day zero of the vacation, we then run about a 45 MPH average for as many hours as I can slog through to get where we are going. The trip home is more leasurely with many stops along the way, but the last day is again usually a big driving day.
I have found if we try to leave on Saturday morning from the house a leasurely breakfast followed by last min. items gets us out the door quite a bit later than I would like. On the other hand if we do all that Friday evening and Saturday morning we wake up in the RV; quick showers with some coffee and bagels then we are on the road, typically by 7, 8 at the latest.
So for actual mileage, our regular vacation (Round trip: ~Palm Springs, CA to Cannon Beach, OR) our biggest day is the first Saturday and we go from Independence, CA to Grant's Pass, Or on that day. ~600 miles, it is a long hard day to be sure! and the last day we are normally exhausted and we end up driving from somewhere near Sacramento back to almost Palm Springs. We have 2.5 travel days and we cover 1150 miles in that time. So I guess the average is 450 miles per day, but it works out more like 200, then 600 then 350 on the last day.
If I were retired I would be happy to go 300 miles per day on travel days, but my vacation time is precious and I want to spend it in specific destinations. (Often in Cannon Beach, OR oddly enough.)
Jeff