I drive an Ford Excursion the size of a city bus. Four captains chairs and a third row bench seat. We remove the bench seat and put in a full size mattress. Then we drive in 4-5 hour shifts while the other sleeps. We take a cooler of food and drink and only stop for fuel & bathroom breaks. We arrive fresh as a daisy. There is also a dvd player in the back in case you want to catch a movie. :) With the 44 gallon fuel tank we only had to refill twice along the way.
...and there you have it...the REASON there is no snow in South Dakota...or anywhere else along your route.