Writing vast books is a laborious and impoverishing madness: expanding in five hundred pages an idea that could be perfectly explained in a few minutes. A better procedure is to pretend that those books already exist and to offer a summary, a commentary.
Introduction to 1941 ed. of The Garden of Forking Paths
surely Mathias Enard's Zone fits the bill (a 500 page, stream of consciousness story written as a single sentence)