I drove from Connecticut to Oregon about as straight through as I think humanly possible, with no drugs. I worked wednesday night till 12am, fell asleep that morning at 3 am and got about 4 hours of sleep. I woke up the next morning at 7am (Thurs), packed my last bit of stuff and left around noon thursday. I then drove all the way to the other side of Chicago before I took my first nap, which was around 2 hours long. Then I drove from the west side of Chicago to Cheyenne Wyoming without stopping. I took another 2 hour nap in a sketchy truck stop in Cheyenne. From there, I drove straight through to Bend, Oregon. I got there around 8 pm Saturday night.
Did this alone, with nothing other than 4 or maybe 5 sugar free monsters. And a LOT of music. Then again, I love road tripping and I love the "zen" of the road. Even the flat parts of the country. I like counting mile markers and doing arrival time math, or even calculating my actual speed. Gas and where to stop. It was a fun trip, and I will always have good memories of it.
My only advice is get some adderall, extended release. 20 mg should be fine. That will help for sure, take it when you are starting to get tired, and you will have another 6 hours in you EASY.