If it's just for a small amount of time and the heat stays on in the house, it's not a big problem. They do just fine at room temp for a while. There are some things you can do in order to prepare for storms and power outages though.
I have my lights on a computer battery backup. That easily handles outages of up to a few hours. I also keep a couple of charged deep cycle boat batteries in the basement. I have a power inverter for them so they can be used to keep the lights on (a couple hours on, a few more off) for quite a while. For longer outages (weeks) then having a generator and fuel is probably the best bet, but more expensive - and you need to maintain the fuel and replace it as needed.
I also have a bunch of 72hr reptile shipping heat packs. They don't get dangerously hot and stay warm for several days as advertised. They are very much worthwhile. I use them for camping trips as well. They expire after a while so I buy a years worth at a time (10-12) and make sure to replace any that have expired.