How long can you go on a 50 amp extension cord?

I see no reason whatsoever why you can't run your RV on a 100' 50A extension ..... but do you have any idea how heavy that is going to be? I believe 50A cable is 6AWG. That is going to weigh a ton! I built a 100' 30A cable for my previous ClassA.....out of 10AWG cable from Home Depot....worked great but a bit of a pain to coil up and store.... A properly sized 50A cable is going to be a lot worse.......but again, yes, it will work fine.