What is "subtly obvious" from reading this thread is that many generator folks may be using way too big of a generator for the job ... hence producing more noise than is necessary.
What's needed is a little tiny generator that will keep the batteries from running down while the batteries are powering (directly ... or through inverters) low energy items such as TVs, computers, CPAP machines, phone chargers, etc..
We have a big built-in generator for the A/C and for emergency heat should the propane furnace system ever fail or the propane run out while camping. We also carry along a 650 watt four-stroke generator that is only 54dB loud at full power. The inverter Hondas can rev up way louder than 54dB under loads above 1/4th, but our little generator is never louder than 54 dB. Our traveling friends also have the same model and often when they are running it, folks stop by to ask them "what on Earth kind of generator is that, anyway?".
RV campers need a small generator for small things, which just might help remove some of the animosity felt toward their use of too-loud (AKA too-big) generators.