Hi Leslie,
We're in Michigan with 7 chickens and currently in a deep freeze. We didn't want to run electricity out to their run so I came up with a low tech way of keeping the water from freezing. I turned a cinder block on its side and placed two large candles, that I set in tin cans (a cocoa container and a 28 oz tomato can) into the two cavities of the cinder block. Then I placed two bricks on top of the cinder block to elevate the metal watering can, allowing air to get to the candles. It's worked great this week. Only when the temp reached way below zero did it begin to ice up slightly. I'm not concerned about fire because this is set up outside of their coop, in their run, surrounded by ice and snow, with no flammables nearby. Also, we are home all day, going out to check on them frequently and the coop/run are near the house within eyesight. I liked that I could use up candles that I don't tend to burn in the house and that I didn't have to run an extension cord out to the run. 
Good luck with whatever you do!