Never hurts to have too much wire!
You will need one pair for the run up the fridge cavity and out onto the roof that will connect the solar array to the charge controller and one from the controller to the batteries. Best to leave extra length coiled up for each run at both ends.
As a German buddy of mine says (he installs hi-tech wiring in custom homes) " vire ist cheap....labor ist not!".
You sure don't want to be a little short on any of the runs, as any connectors or splices have the potential for voltage drop.
While you're at it, it would make for a really easy (and quicker) installation if you got the voltage sense probe and the battery temperature sense probe NOW from AM Solar and ran them from your intended battery location to the intended charge controller location along with the battery charge line.