How many miles and hours you drive is up to you. When you are tired, stop driving and take a rest break. Plan on a rest stop at least every two hours. It also depends if your significant other will drive. Plan your trip with alternate plans that may need to be used in case of heavy traffic. Be optimistic but keep things that could go wrong in the back of your mind. Personally, I leave before sunrise and try to drive 500 miles or 10 to 11 hours whichever comes first. Sometimes I have had to sleep in a rest area due to traffic accidents and could not reach my planned stop.