You could use a portable ac to help with the temps, but it would have to be a two-pipe system. There's no inside air exchanged with that style. Depending on the neighborhood, you would still have to have vents showing in the window and that could raise questions. It would be easier to hide than a regular window unit. Always put something in front of it to make it not so obvious with a two pipe.
With a central AC system and without supplemental AC, your room is gonna just run warmer no matter what you do including keeping your door open. That's just a fact.
In those damn suburban nut to butt housing developments, I would be up on my carbon filters and rely on them the most.
If you did do a two pipe supplemental system, I would try to fit the most amount of tents I could! Your current cost would go up, but spread over more production.
What do you have set up now? What tent?
How's that used gorilla tent doing? I think we've had ours about the same time.