We dry camp on a regular basis. Our battery easily lasts a weekend... by thinking of the camper as a big tent. Do not use camper lights at all - use battery lanterns and flashlights. Save the camper lights for the midnight bathroom use. Do not use the camper's propane heater if the night is cool - the blower fan uses more energy than you might think. Avoid using the vent fan(s) if possible... but sometimes you have to!
Making morning coffee on the stove top with a percolator will usually easily warm up the camper. Always remember to open windows and ceiling vent, at least a little bit, for fresh air.
Showers are no problem. Turn on the propane water heater about 20 minutes before your shower. Just turn on the water pump when you need it, off when you are finished. Learn how to do a "Navy" shower - very quick wet down, turn water off, shampoo and soap, turn water on to rinse off as FAST as possible. You might be impressed at how little water you will actually use when you get used to it. I then turn off the water heater - it actually uses very little power, but it is one more thing to save energy by doing.
We've gotten to the point where we kind of prefer dry camping, especially in the Spring and Fall (mid summer I am willing to give in and use an air conditioner... lol!). A lot of dry campgrounds have larger campsites, or are nearer to beautiful places to hike and bike. In my state, Connecticut, most state parks do not have hook ups, so dry camping is usual here (this is changing, and the state is adding hookups, and I have mixed feelings about that!).
As for your generator, if use the tips mentioned in this thread, you will probably find that you simply will not need to use it.