I did something similar some years ago as a personal project to keep an usable and searchable local copy of the interesting stuff found online: a web app that fetch Pocket read later list, convert the articles to pdf stripping not useful parts (and ads), archive them in a Dropbox folder and finally delete the Pocket elements themselves to keep the list clear (and obtain a little more privacy).

Soon I will get a new e-reader, perhaps I could refresh and publish it on GitHub :)