I would buy three more things based upon my experience w/o power and eventually water.
Two buckets from Lowe's w/ lids
25' rope
Bathtub Bob
https://www.amazon.com/WaterBOB-Emer.../dp/B001AXLUX2
You will have water until the tower runs dry. Then use buckets and the local pond for filling the toilet.
The tub water storage bag has all the potable water you need. Which you fill once the power is out. It's a better option than your water heater tank due to the risk of Legionaire's.
For 50.00 you get a lot of knowledge that you will live in relative comfort.