andrewpetre wrote:Curious since I don't know -- is it common for RVs to have outlets capable of sustained 15-20A current delivery?
Probably not.
My recollection of "older RV's" is that they typically have a 30A shore power connection, and a similarly taxed generator-set. I'd expect that when the heater kicks on, the generator engine will slow down, the voltage will drop, and if you're trying to pull a shot, the pump will slow down (and lose pressure).
If you've absolutely got to do this (and it will be stuck inside the RV for a long time), see if you can get a propane-fired lever machine, and get that hooked into the LP tank. Of course, propane fired lever machines aren't cheap, just like everything else in the RV world.
Aeropress, Toddy, or pourover cone, along with adjusted expectations, are a MUCH better fit if your friend is not seriously "into" both espresso and RV'ing.