I agree the poor man's generator isn't a perfect solution, but it is functional.
As for generators in federal parks - for starters they must meet spark-arrester rules, which the cheap ones don't have. 2nd, if they are too loud, and all of the cheap ones are, they can tell you to shut it down.
2008 FR Salem 26TBUD
2010 FR R-Pod 171 (2009-2015)
2010 Chevy Suburban
Honda EU3000is inverter-generator