I have upgraded my Vista 27N to be able use 45 Amps Shore Power. This allows me to use microwave or hot water heater and air conditioning at the same time and never trip a 30 Amp shore power breaker.
I did this by looping the power for the Microwave and Hot Water Heater that feed from a breaker to a Energy Management Box thru the basement power compartment. When operating from generator or with only 30 Amps shore power the plug and socket are connected together as shown. Took a couple of hours and about $ 20 worth of parts, given I already had the 12/3 extension cord and adapters.
When I have a 50 Amp outlet , two 30 Amp outlets, or a 30 + 15 Amp outlets available I unplug the connection shown above and connect the plug above to a second shore cable, a 25 foot 12/3 extension cord, and just run it out the basement the same way as the 30 amp shore cable.
At the pedestal end, when I have a 50 Amp outlet, I use this 50A to 30A + 15A adapter that I made by modifying a 50A to 30A with a fuse protected additional 15A outlet.
At the pedestal end, when a two 30 amp outlets, I use a Camco 30A male to 15A female adapter on the 2nd 30 amp outlet.
When at a pedestal with 30A and 15A outlets I just plug in the ends of the two cords.