Motors and VFD actually like the cold. It will not cost any more to run them in the cold. It's not an issue. The grease in the motor bearings will not cause more friction / load when it's cold. As soon as the motor shaft begins spinning it will warm up the grease to normal temperature. Heat is what kills motors and VFDs, but we're talking extreme heat. If you can stand to be in the shop, the motor and VFD are oblivious. Their operating temperature ranges are well below/above what you as a human can stand.