I think the problem here is that we keep throwing 100A into the mix. For RV use...one double pole 50A breaker (essentially two 50A breakers tied together) using 6AWG on both sides. Easier to think of that as two 50A lines than 100A total. It's kept separate from the breaker all the way to the RV panel so that both lines separately carry 110V at 50A max.
2012 Chevy Tahoe LTZ - HD tow package
2017 Rockwood 2703WS Emerald Edition