I use the Inkplate 6Color for some similar projects. Built-in ESP32 controller, so no Pi required. Can be fully battery-powered, so if you make intelligent use of the deep-sleep/wake schedule, you can stretch that battery charge for a couple of weeks. My favorite one is a red "On Air" sign that hangs on my office door (used for meetings and recordings.) I just trigger a shortcut on my Mac and it automagically updates my status and mutes my devices. They have example open source projects for weather displays, news, Google Calendars...
I have a similar project too! I have an e-ink display connected to a Pi Zero that shows just a "Yes" or "No" telling me if it's going to rain outside in the next three hours. (On a second thought, maybe I don't need a 7 color display...)
What was the name of the eink computer that was on here last week? I can't find it back for the life of me. I desperately want a flat white display for work. Reading technical grant proposals on a regular screen is killing my eyes.
https://soldered.com/product/inkplate-6color-color-e-paper-b...
Cheap e-ink projects are super fun and useful.