Know when to fold 'em (or, at least, stop reading 'em)

I have a bad habit of being a completist.  This is a very bad habit indeed when one is working on a big literary history (known hereafter as Book 3 1/2) of an omnipresent nineteenth-century genre, because, of course, one cannot read every religious novel published in Britain between 1800-1900; I've identified well over a thousand of them, and stumble across more of them every week.  Unlike Book 2, which had a well-defined corpus of novels to work with (historical novels! religious! about the Reformation! written in/available in the UK!), Book 3 1/2 is about a pretty amorphous field (religious novels! written in/available in the UK!); this is where Moretti's "distant reading" certainly has its appeal.  The difficulty is not so much "where to start" (I've been reading this material for fifteen years!) as "when to stop."  Last night, after I surfaced from the first week of classes (hence the radio pixel silence), I pulled up a book from my to-read list, an anonymous novel published by John F. Shaw called Christine; Or, the Bible Girl.   And I read it.  And I knew exactly what was going to happen at every step of the way, because it did absolutely nothing unusual or innovative for a novel of the 1870s.  In that sense, Christine demonstrated that, yes, certain tropes had hardened (into what felt like literal concrete, reading-wise) by the last third of the Victorian period--but from a literary-historical perspective, I already knew that.  If I were to write an article solely on J. F. Shaw's output, the novel might come in handy, but I doubt that it will rate even a single mention in Book 3 1/2.  At this point, as I come near the end of my "let's read" period and move on to the "let's write" period,  I need to be much more strict with myself about post-holing this kind of fiction (i.e., read X number of authors from X publisher during period X-Y), because too much of what I'm still reading doesn't teach me anything new about religious fiction and its various subgenres.  Which is another way of saying: here is what I can write about now (at this point, quite a bit); there is what I can write about after I do more reading.