Driving straight-line freeway with exit ramps and the occasional streetlights is WAY different than blasting around back country roads in the dark. Besides the potential for off-road excursions, the chances of making a wrong turn and becoming hopelessly lost are a lot higher.
I agree that we will need very experienced group leaders and everybody else should have at least one drive under their belts. One option would be to have a dual drive. One Friday night and another Saturday morning. Since the contingency plan for bad weather is to go Saturday morning anyway, we could start a sign-up list for a day drive the next morning. Maybe start it a little later, so the people from the night before aren't up at the butt crack of dawn. If we keep the same pace we ran on Sunday, I could start as late as 10:30 or so and still be able to make it to work by 3:00.