I gave it a very short search back when it broke last year. I went with the cheapest way to get it back up and running which was just convert it to a desktop. She never goes anywhere with a laptop in the first place so there was no need to make it portable again.
She’s retired and just used it to surf the web. A Chromebook would work perfectly for her if she was not dead set of having Excel for her recipes and bill tracking.
I practice this same thermal battery idea as well with an extra tip of having a couple of fans on timers (sun up to sun down) that sit on the floor and blow the cold air up. It makes a significant difference, especially if you can sit a fan where the cold air from the AC falls to the ground.