Shouldnt take too long maybe 2 days at the longest. Your ticket will have a departure and arrival time and is pretty accurate if the weather doesnt mess things up. Bring lots of food. A coffee mug and tea/coffee is good, fill up on hot water at gas stations which youll be stopping at occasionally. If on a long layover ask people at the station that look like theyre picking up/dropping off people if theyres any other stores around the area and maybe see if they can give you a ride to save you walking time.