Before I started flying out there, we would caravan the team out to Ohio from Denver - a 24 hour drive time. We'd take 3 days out, 2 days back, and cover over 1200 miles. It was a blast!
I also went to school in Nebraska, and would regularly drive the 8 hours home and back by myself.
ETA: Just remembered the big trip we took as a family vacation one year. Drove from Ft. Collins, Colorado to the Outer Banks/Cape Hattaras/Okrakoke and Cherry Point (where Dad was stationed as a Marine and where my sister was born), North Carolina. In July. No air conditioning. Towing a camper. 2000 miles.
I think I was between 5th and 6th grade, and my sister was between 8th and 9th. It was actually a fun trip.