I have a small 2 door (freezer and fridge compartments) 3.2 cubic foot dorm fridge in my trailer. It can struggle to keep up when the ambient temps get above 85F. I suspect that in these temps, the compressor life is exponentially shortened as it runs a lot.
If you want to go a similar route, buy a small 3.5 or 5.1 cubic foot upright freezer then use the temperature controller and divide the freezer with the bottom half being a freezer and the upper being a fridge. The trick is to use a good piece of thick insulation to separate the 2 compartments. There are some Youtube videos that demonstrate this.
Edit:
I also mounted a 120 mm computer case fan at the back base of the fridge and it sure helps to keep the compressor temp down.