Good point. For an extended outage in cold weather all of my snakes will be moved into bags and bins, and then stacked up in a small room like a bathroom where a space heater could keep them all around 80*F. It's much easier to do that than try to run all of their t-stats, heat tape, RHP's, etc.
Cooling is a bit trickier. While most of my snakes may be uncomfortable at high temps, we do get summer days that can top 100*F and my BRB's really can't go much higher than 88*F ambient without risking neuro damage from what I've read. On those days even the tap water is fairly warm. So I keep water in the refrigerator to refill their bowls during the heat of the day, or give them a light misting if needed.
I wish I had a cooling issue but up here I rarely need cooling! I can only wish! We still have 7 feet of snow!