Well it's pretty simple-if the cable has moisture in it and it is cold enough in the barn to freeze, its frozen. Just put some heat to it to thaw it, then I would get a cable-luber and force all that water out of it. The cable is quite small so don't force it otherwise it will break.
The cable goes through the console and of you look on the passenger side wheel well low at the back you can see where the oil and coolant lines come through. Force heat back in there and it should get the cable warm enough to thaw.