The Kobo ereaders have had Pocket integration for a while now, and it works great offline. My usual routine is to find interesting articles on Hacker News, and if they are longer than a page or two, click the Pocket button and read them at home on the ereader. A few don't render well (the article on Arrival/Story of your Life not being a time-travel story was a recent fail), but generally it works great.