Hi MsDisney23!
Those of us on the DISabilities board have talked about this topic (insulin and a fridge), and it is really inconsistent at Disney. I have talked with them at the Swan, and even though I take 3 different medications that need to be refrigerated (none of them insulin), I still have to pay if I want a fridge in the room. What people report is that sometimes they won't charge you for a fridge for medical reasons and sometimes they do charge you, even if you need the fridge for medications.
What the different resorts have told others in the past, is that if you need to refrigerate something then you can do that at the front desk, which just doesn't work well for me since I take my medications at different times and don't want to have to go down to the front desk in my jammies to get my medication(smile).
I wish that it were more consistent and not just who is lucky that day(smile).