We were one of the unlucky few to have had power go out this past week in the ice storm for five days. We only moved out of the city in September so we didn't have a generator or know anything about how to hook up a car battery to anything etc.
My husband and I took turns boiling water and putting them in hot water bottles and putting them in the tanks along with wrapping the tanks in towels and putting plastic sheeting over most of the top to keep the heat from evaporating too fast. We did this for the first two days, thinking the power will go on any second - then checked the propane tanks to find that they were very very low. Our neighbor lent us a kerosene heater but that thing let out some awful fumes, and even with some windows open we aborted that plan after a day and a half. For a day or so we let the water go to room temperature as we were so exhausted from not sleeping for days and hoped that they would start to go into hibernation without too much trauma afterwards. Then the last day we were lucky enough to find a propane camping heater for sale, the last one, at a camping store and put that in the turtle room.
Once the heat came back they quickly came back to normal life and are acting like usual and I am so thankful that so far as I know at this point, they made it through in one piece.
We are looking into getting a small generator for future use for sure because we have 4 other mammalian animals and would have a hard time getting a hotel room or even asking any friends to take the WHOLE family in. Here is a picture of Ichigo reviving in her warmed up water.

1.1.0 - RES - Ichigo & Pan-kun
1.0.0 - Pitbull mix - Coleman
1.2.0 - Kitties - Jojo, Spidey, & Hopi
& hubby David
and now.... porch cats - Macy, Tink & Henry
http://ichigotheturtle.blogspot.com