Use portable lights instead of house lights. The water pump will kill the battery for sure, so use it sparingly. Your tow vehicle will charge the battery when plugged in. So hook it up and run car for an hour a day. Depending on your TT charger that could put 30 amps back in the battery. Use the campground showers or use baby wipes. When you get some extra cash add a second battery. As for a future generator stay away from the cheap loud ones and wait until you can buy a Yamaha or Honda inverter series gen. They run for a long time, use little fuel and as importantly they are quiet. So you and your neighbors will get along better.