If you have a a good (Nascar) generator,, By that I mean one that is really really loud and rattles and has a ton of racing stickers on it, then you should be fine with two 12 volt Wal Mart batteries,, couple of group 29 batteries should provide lighting and run the water pump. Keep the fridge on propane and you'll be good to go!!
Had our trailer in the Vegas infield, they put us next to one of those portable light generators,, It had two open 110v plugs so I ran a cord off to it at night and we were good all the way till Monday morning with power!! For $50 they even flushed our tanks and refilled our water tank!!