There was also this, last summer:
I'm in the south too and faced a long-term power outage with the opposite problem - heat - but the same issues of dealing with extreme temperature and oxygen. I bought battery air stones and was dismayed to find that even the ones marketed as "silent" made a racket. Still, they worked.
It was temperature that ultimately forced me to take drastic action. I guess we would've toughed it out but for the fish, who were at our mercy to control the environment. We evacuated. I put them in a jar, got into a car, drove to another state (one with electricity), walked into a store and bought small 1g aquariums. Then stayed in places (hotel, relatives) where the tanks could be plugged in and the room was within comfort range for both man and beast.
If faced with your situation I think I'd probably do a combination: get small easy-to-carry tanks, put in battery air stones, and then take them to the fireplace room. I've found that with the little bitty tanks, whatever temp the room is (i.e. my human comfort range of 70-75) the tank stays in that range too without needing the addition of a heater. As mentioned already, a blanket would help that.