This sample by Ivan Herman of the W3C, Portable Web Publications, just about hits the limit of 5DOC’s prototyping site with the HTML download weighing in at +20mb. Note: there is an embedded video on page 27.
At the moment, on the eve of the W3C 2016 TPAC Conference, there is still considerable debate about what is meant by PWP and even suggestions that the name should be changed again (it used to be EPUB+WEB).
There is some consensus that there should be a separate effort to more precisely define offline capabilities and requirements. Foreseeing that this would happen, 5DOC.org has helped establish the W3C Offline-URL Community Group in order to update the 1994 File URL scheme(file:///) and add zip compression and containers.