Heck yeah! I would think you could keep it from freezing by having it raised up higher towards sunlight and wrapping it in black, even black plastic contractor bags. Just like those solar camping showers, or those passive solar water heater systems that sit on the roof. And keeping the water circulating with a fish pump bubbler.-idk if your off grid. I use large bubblers and heated hose to keep my 4000 gallon compost tea IBC from entirely freezing in the winter. The bubbler would keep the water fresh too. I would think using pipe insulation for the main hosing on the rabbit water would keep the hose from totally freezing.