When we had a multi-day (6 days I think) power outage a few years back our biggest issue was getting water for our horses, in the volume that they need (we have a well). We could buy sufficient water, but the horses drink a LOT of water. Luckily the township responded to our call and trailered in drinking water for them.
At the time we had an above ground pool, and I swam in that to clean up a bit, but after three days or so the pool water started turning bad, so I had to turn to minimal sponge bathing. We'd go to bed when it got dark, and it was summer in the upper midwest, so home heat wasn't an issue. We had to toss a lot of refrigerated food!!
Ken