Hi PortiaD. :thumb:
The good thing going for you is that you know when the power outage is going to be and you can prepare things to get through.
You may have already sorted out these questions and suggestions below but no harm in asking.
How you are going to heat the water when you do your water change on these days.
What are you going to do with your filter media?
After 8 hours or so with no water movement your BB will start to die off and be unusable.
If you can get your filter media and put it in a bucket full of tank water and place an air stone (with one of your battery air pumps) at the bottom to circulate the water around it, no need to heat it if your outside temperature is as you say.
Good idea not to feed for day or two before.
LOL. You are correct, blowing into a bag full of fish or your tank isn’t the smartest thing to do, as you say it is only adding carbon dioxide. I do hope some people were only joking with this comment...
Good luck, hope all goes well for you.