Update. The fridge is working fine and I'm pretty happy with my remote temp display. I mounted my exterior sensor for my indoor/outdoor temp at various places in the fridge for a day or so each(high and low, right by the freezer, and down in the bottom drawer). It reads the same at any location in the fridge. No surprise really but it was worth experimenting. On the highest setting, 7, the fridge will get down to 32 degrees. This is with outside temps of 60s/70s in the afternoon here and 50s at night. It takes a good 24 hours for it to get down that low though. On about 5, which is where I've always kept it, it stays pretty consistently at 38 and gets there within a couple hours of turning the fridge on from room temp. My plan here is to figure out how to load my fridge where I can get drinks as cold as possible without freezing, and of course without freezing any other food. I also placed a bottle of water at different places over the past few days and the water bottle has not frozen.
Conclusion: The Truckfridge will get about as cold as you want it to without freezing. I'll be paying a lot more attention to my inside temps in the warmer parts of the year since the display is right above my head on the overhead console.