From my experience you get a better value with this size system to spend the money on a larger panel or more efficient loads then a MPPT controller.
I think adding another 100W panel will be enough to run the fridge but 2 panels occupy 1/2 of my rack. I need rack space for future RTT. Returning the panel for a larger load one is not ideal as I hate having to run the wires again. In a meantime, the panel will keep my battery top out.
....iPad using IH8MUD