RVer's if they need AC power for AirCond they use a genset somewhere away from others or go to a CPark and plug in.
It ain't to done thing to camp by others with your genset running for hours, one reason they are being banned in camping area's.
RV ac units are huge power consumers so your going to need a big battery bank and (usually) sinewave inverter to run it.
Viesa truck evaporative cooler
http://www.viesa.ca/ are one way of doing some free camping cooling but even then the bank needs recharging to power it. Day
Certainly not the solution but would help cool (a bit) or try one of those portable EC advertised on TV a the moment. 12V fans ???
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