My husband likes to fly RC planes, or run his RC monster trucks. While you're in the motor home sewing send him to nearby towns to scout out fabric stores. There's reading, hiking, fishing, boating, swimming, shopping, etc. or he could get his own hobby--wood carving is a wonderful hobby, can (and probably should be) done outside, perhaps he'd like to build bird houses. You could leave one everywhere you camp. Let your friends and family know his type and color scheme to see if they can ever run across one. OR, he could take the kids on an exploration excursion--pack them a picnic lunch, bug spray, a small first aid kit and sunscreen and send them off. Then you have the whole day to yourself so that you can sew.