We're fortunate in that we can drycamp about the same way, but with a little tiny 650 watt four-stroke genny (no longer available) that just sips the gas and is very quiet. It, along with the converter, can put up to 40-60 amps into our batteries every 5 hour run on it - which takes about 1/2 gallon of fuel. Our AGM batteries make this possible.
The main difference is we don't have to be constantly vigilant regarding our power usage because we're guaranteed 40-60 amps into our battery bank any five-hour period we choose. Solar is of course great as another source, but if we had solar we would still back it up with our small powerhouse. We also use our air conditioning as needed via our fairly quiet built-in genny because we don't want to be restricted to only boondocking in mild temperatures.