Cooling truck box for sleeping with Ac

Hi!

I’m planning to sleep in a 15’ U-Haul box for couple nights in the desert (max is 80 degrees during day I think)

I have a 3K generator that can run for 10-11h on 50% load

Was planning on buying 8/10/12k BTU portable or window ac, and putting it inside the box truck (Having the door closed enough for the exhaust to be there or for window AC I’m looking for a U shaped AC that the door will close into it)

Will it be able to cool it down without insulation? It’s for 3 days trip purpose so I don’t mind running the generator all that time.