There's something about the cabinets the fridges are placed in that causes them to not cool as well. I think it's that they aren't ventilated properly. If you leave the door to the cabinet cracked a little, the fridge will cool much better.
I almost always have to turn the temperature control knob to a colder setting when we get there. Disney usually has it set at 3 and I have to raise it to close to 5