:( That's awful! I have relatives in Kansas City who were without power also for a long time. :(
There's actually an oxygen disassociation curve that happens with increased temperature. I.e., the lower the temperature of the water, the easier it is for it to hold onto the amount of oxygen in it. In medicine we use the curve to determine the oxygen carrying capacity of blood per temp, etc but I suppose it works the same for water also. You fight how much oxygen is in the water not only by using an air pump, but also by using frozen clean pop bottles floated in the tank. In summer months, I keep 10 or so in our deep freezer in the basement, and use them as needed even when the power isn't out. Also, they are filled with frozen clean change water so I have that also on hand if needed.
The major (longer) outages I have here in winter, I control with as many water changes as I can, mostly. I keep several buckets of change water in the basement at all times. KNock on wood, haven't lost anything that way yet... the major thing is water temp, but heateding change water on camp stoves seems to do the trick there.
So sorry for your losses,
Laurie