I just put my Carapelli in the frig. I have both extra light that I use for cooking and extra virgin I use for flavor.
Extra light--hardened up
Canola oil IS mostly monounsaturated fat, which will harden in the fridge.
Polyunsaturates, like corn and soybean oil will remain liquid in the fridge.
Monounsaturates, like olive, canola and some nut oils will harden when chilled (this is why natural nut butters don't seperate if you stir them and put them in the fridge).
Saturates, like butter, cocoa butter, palm and coconut oil will be hard at cool room temperature but melt at body temperatures.