Don, Nat, Danny, and Triss covered a large margin of distance before deciding to camp out in another town. They decided to use one of the buildings for shelter, clearing it out, then set up their camp. Don decided to take watch while the others did what they needed to do. The only reason he was resting was that he promised Melissa he would rest when he found time to.
Since this was a good time to rest, he decided to rest. He did not want to break his promise to Melissa. If it weren't for the promise, he would continue onward, leaving the others behind. He wouldn't abandon them, so to speak. He had already drawn up directions leading to his home base, not in the direction he was heading.
