When I was young, and dumb, I drove from St Louis Mo, to Denver Co, in, 17 hours. almost 1000 miles., on my way to my new station at Hill AFB, Utah.
1968, the interstate across Kansas was under construction, so I took roads across the northern border of the state, 2 lanes almost the whole way.
I only got out of the car for nature calls. Full service gas stations, and full service at drive ins meant you didn't have to get out of the car.
If I could have got a pilot's pal, I would have used it.
A 6 cylinder Rambler with no AC, in July, and just me.
I used to do trips like that all the time.
Maybe that's why now I have a hard time going a hour without a pee.