Thank you, Hemmi! I live in an urban area and still wasn't able to connect using the 3G. And according to Sony's website, there's no firmware update to this model, as far as I can tell:
https://esupport.sony.com/US/p/model...d#/downloadTab
I guess I'm stuck with physically loading books onto it, but that's ok. Won't be the first or the last time I do it! :-D