We have a single 115W panel and almost always dry camp. I've taken along our Kipor 2000 generator "just in case" but have only needed it once. I've found that with 2 6v GC2 batteries (bought at Sears) and the single panel we can go indefinitely if the sun isn't blocked by trees, and if there are lots of trees we can go for about 10 days during the summer and 3-4 if we have to run the furnace.
We have LED lights, shower at the bathhouse, don't have a TV, and the kids know the drill (turning lights off and such)...