I would say it's personal. Have you driven through the night before? It is a bit different. It's cooler, scenery isn't the same. I find sunrise the hardest time slot, that's when I get tired, doesn't matter if I have been driving for an hour or 10 hours.
I can tell you once driving back from Montana across hwy 2, we thought we would make good time and it would be cooler. We could not go more that 15 to 20 mph, do to all the wildlife on the road. Never had seen so much in my life, even had a big owl swoop the windshield.
Lately, I leave ether before or after rushhour, and drive until 11ish, then pull over for the night, and then start up again early.
2012 Jayco X23B
2020 Ram Laramie 3500 SRW Air ride 50Gal fuel tank.
2007 Dodge Dakota Quad Cab (retired from towing)
Equal-I-zer 4-Point Sway Control