You might want to look into one of these portable air conditioners to supplement what you have. 40' trailer sure is big...
WAY too big for me hehe...
Kids went to the VA beach last year with the inlaws who was setups at an electric site on the beach. They had two or three tents setup close by and one of them had something like this google photo using a portable house window unit and some duck tape..
We have done something similar on an extended stay in the woods with our POPUP. Have setup a 8K BTU window unit in our unused tent bed side sticking out the window flap all tapped up with ducj tape. We could run this size with the 2KW Generator when allowed to run the generators there.
Roy Ken