+1. An ESP32 can fetch the image, display it, and go to deep-sleep with a much lower power output. The battery will last longer, but getting it much further is harder because electronics will degrade as well.
https://steve.fi/hardware/d1-epaper/
It wasn't easy as I couldn't get GIF/JPG, or similar, working. As the library I was using used a buffer my RAM usage was twice as much as expected. In the end I used a simple home-made RLE-kinda image encoding. Then I'd stream those updates.