Trying to get away from my phone more, and an e reader sounds like a good way to get myself to read more. Kobo is sounding like the most recommended one based on some googling, but I’m also ok with jailbreaking something like an older kindle from eBay. Something that plays nice with Libby would be ideal but not required. 
The BOOX Palma 2 runs Android so you can easily install Readest and Syncthing on it. It’s a really nice size and has decent build quality in my opinion.
I have a boox and I’m really happy with it.