I'm going out on a limb, if it's installed correctly for 'your' area, it probably won't even ice over more than just a 'skim' in the coldest weather you have. 

The only problem I can think you might have will be the cattle 'drooling' water in the building and creating a mess that won't dry or ice on the ground around the waterer that won't melt due to no sunlight and no wind.