How many extension cords can you string together?

" their closest standard 120V outside outlet is located"
It is probably only a 20amp or even 15amp circuit, may even be GFCI protected. Even using heavy duty 30amp rated extensions, you will still be limited to the 15 or 20 amps available at the house outlet.
You maybe able to run the AC, but make sure that your fridge is set to propane only. Limit all other 120 usage. Converter may also be a factor, especially if only 15 amps available, also size of AC 13500 or 15000 unit.

Beverley and Ken