I use the same. I looked for another one at
TSC (where I got mine, last year) and there were none to be had.
You only asked about water, but I'll throw out a couple other things, just in case you didn't know...
Ventilation is important in the winter, perhaps even more so than in the summer. Chickens' breath is steamy in the winter, just like ours. Their poop is moist, and full of ammonia, which will irritate their lungs.
Luckily, ammonia rises, so if the ventilation is up above the birds' heads, the ammonia will be vented out and not accumulate. The moisture will dissipate too, which means less chance of frostbite on combs and wattles.
Some people keep water in the coop in the winter, but I don't. It's another source of moisture, and if it gets spilled, it makes a cold, wet mess.
If you keep your chickens dry, they can keep themselves warm with their down jackets, to surprisingly brutal temperatures. You didn't say where you live, so I don't know how cold you're likely to get. You can add your location to your profile -- the state is fine, or country, if you're outside the US -- and then people can tailor their advice more specifically. What works for me in Michigan might be useless in Florida, for example.