Power outage is over and only lasted a few hours. Thanks for all the advice. My back up battery pack was enough to keep the pump running. The tank dropped almost 2 degrees, but everyone seems to be doing well.
I will make sure to prepare for this in the future.

Glad to hear all is well.
+1 on air pump
+1 on battery operated air pump that comes on automatically when the power goes out.

Amy. I've got a few of these battery powered air pump that willl go on when power is out. PM me if you are interested. Lenny.

I experience plenty of power outages and have never done anything to try and keep powerheads, heater or oxygenation going in my tanks.
It's not so bad since we were moved to a different power grid but we used to have at least 2-3 power outages a month and many have lasted longer than 12 hours
For what its worth - I have never lost anything in either of my tanks due to the outages.