Should be fine providing you purchase an efficient fridge. I have a guy running a 100w stand alone system(Not connected to the vehicle) for a couple Years now in the Aspen area.
I have since upgraded my solar on my 80 series. Im running a flexable ultra thin (.12")100 watt panel.
Phil, please provide more details about the solar panel you're using; i.e., make and model. Plus I don't see any wires; did you drill holes in the RTT top?