For short term, and this is what someone else recommended that mght work. Take a plastic container and punch a small hole in the bottom. Fill it with tank water and suspend it over the tank. The water will drip slowly back into the tank and will keep the water oxygenated. The only problem with tis is that, depending on the size of the container, you will need to refill it every couple of hours.
The other thing is a battery powered pump with an airline hose and bubbler at the end. Your LFS
may have them or other places like Petsmart or other general pet supplier that sells aquarium supplies.
As for keeping the temp up, wrap the tanks in towels and tape them down. When I lost power last winter, I borrowed some of the insulation from my basement and wrapped the tanks in that. I now have styrofoam sheets that are sized to the sides of the tank on standby. I can effectvely box in the entire tank, sides and top.