In Texas, are you kidding, piece of cake! You folks hardly know what a winter is compared to what we have up here in the north.
They do fine here in Michigan when its 20 below and the windchill is minus 50. They really seem to not care too much. I couldn't even get mine to use the insulated nighttime house I built for them, they would rather just sleep outside in a pile.
The only thing you need to do in winter is provide some kind of unfrozen water source. A simple bucket is fine, just as long as it has a few gallons of water that won't freeze and is deep enough for them to dunk their heads in. I never even bought a heated bowl for mine, just went out and dumped the ice out and replaced with hot tap water a couple times a day, which they really enjoyed. Heated bowls are sold at feed and farm stores. that would work great.
Dad, if you read this, nothing to it (sorry if that's NOT the answer you were hoping for!).