This comment right here is the actual "Mildly Infuriating" part of this story. I bike to work, recycle trash and use the train for my vacations, all in an effort to reduce my personal carbon footprint to save our dying planet. And then there's egoistical assholes who leve their cars running for days on end just because they can't handle the mild inconvenience of a night outside.
No offense to you though. Your story sounds like a one time off due to very special circumstances.
Or... hear me out... You don't use an AC at all! Especially for camping.