The Frigidaire Top Freezer Refrigerator is a typical style of residential fridge you will find in an RV. It is a good reference on what to expect when wanting to run on off-grid solar.
This refrigerator is listed as having a 6 amp draw at 120 volts with a minimum of 15 amps required to run.
The 15 amps is most likely only at startup. 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.