Never needed it at an RV park, but at county fair grounds and some other spots I have needed an extension. Since I don't normally need the AC I'm happy with a heavy (12 gauge) 110V 20A extension. If I need the microwave or TV, the batteries provide enough power, and the shore power will recharge them when I'm not drawing big power.
A 30A or higher extension is hard to work with, big to carry, and most of the time I needed an extension 30A or 50A was not available, so it would not have made a difference.
I can also use the 12 gauge for other things, so it is multi use, and space is always at a premium.
2006 Patriot Thunder C13 Allison 4000
2010 Ford Flex Ecoboost AWD