I just did another 6000 mile roadtrip in the old focus CA to MN and back.
During the three day drive back, there were several interstate closures that forced route planning changes. Check the DOT for the states you plan to drive through the day before.
I like to stop every 2 hrs, jog around the rest stop to get the blood flowing a bit (I do not normally exercise).
Coffee and Monster energy keep you awake, but the caffeine dehydrates you which will make you tired. Drink water or gatorade or something other than just coffee and soda pop.
Smartphone is neat in towns, but doesn't work everywhere.