I installed a window unit in the rear of my 35′ bunkhouse. We were full timing in a single location. Moving with it installed was not an option. Fitting the unit in the window with the insulation in the gaps is critical to keeping it efficient enough to make sense. I had created some extra space between the bottom of the window and the a/c unit by tucking the power cord under and out the window. I used the 15 amp outlet on my shore power panel to run the window unit since my camper is on a 30 amp circuit. I maybe could have got by with running it off an outlet in the camper but probably would have constantly tripped the breakers in doing so. TLDR: It’s feasible and it certainly made a difference but can be a giant pain to do more than once much less routinely if you’re moving between sites regularly.