After losing 15 Beautiful DISCUS in an ice storm when the power was out for 3 or 4 days, I bought a generator for my house. Problem solved

If that is not an option for you, you can purchase a battery powered back up air supply for around $12 at your
LFS. You plug it into the socket, add batteries, turn it on. When the power goes out it automatically comes on. As far as filtration and heat....Cover the tank for warmth, try to keep your bio matter wet even if you have to put it inside the tank itself, the good bacteria need oxygen as well as your fish. Some have suggested a battery back up that is used on a computer system. My opinion, WAY too much $ for the short amount of time that it's going to work.