The Kenmore French Door Refrigerator is a good reference for what is required to run a residential fridge in an off-grid solar RV.
This refrigerator is listed as having a 15 -20 amp draw at 120 volts.
From experience, this would most likely be at startup only. The actual running draw on a fridge of this size averages about 720 watts or 6 amps. Depending on the ambient temperature, you may find that the duty cycle for this refrigerator will change when running off-grid. The duty cycle will determine how much power is needed from your battery and solar system in your RV.