If you have never used a portable generator, you should know they are LOUD! Most campgrounds have quiet hours and wont let you run them at night. You wont want to sleep anywhere near it either. So you definitely want a battery system you can recharge during the day. If this is the only load, just about any small gas powered generator should be able to charge it. The 20 feet distance from the house is overly conservative in my opinion (it probably has all kinds of worst case assumptions built in) – I ran a generator on my back porch for 2 weeks after a hurricane. Just make sure you don’t have any open windows near it, and don’t run it when you are not home (in case it somehow catches on fire). DO NOT try to connect it to your house wiring unless you are very certain of you skills. You might also be able to charge the battery with your car in a pinch – but expect it to take a few hours.