Just make a thread when something new is posted about whatever was just posted (so one thread now, one on friday etc.). Surely, this makes the most sense?
P.S. Also I've downvoted because this seems like a pointless meta-thread. Even if we accept that this is an important question (which I do not), I do not see why there is a need for a whole new post instead of a comment with the poll on the last HPMOR discussion post or the Open Thread.
Just do it with one article for the most recently posted batch of 2 chapters. I (and probably others) am exerting way too much willlpower resisting the urge to discuss certain matters on the old thread and spoil it. This shouldn't wait for the results of a poll.
I thought about it, but I still haven't fully grokked the rules and community norms here. E.g. when to post in Main or Discussion, and whether recurring topics should be posted by moderators or particular individuals.
I thought about it, but it was a trivial inconvenience that totally outweighed my strong desire to talk about the new chapter.
My opinion is that we should make a new thread when and only when at least one of these conditions is met:
We want a new thread each update, for spoiler reasons and so forth, and we also don't want overfull threads. So basically what this boils down to (even though I voted "something else which I will explain in comments") is "2 threads, 91 +92, then 93", but with the caveat that if the 91+92 thread fills up way before 93 comes out, we should make a new one, without waiting for 93. With the new, fast paced, update schedule, I doubt this will happen, but in the general case, I think that there is no reason to use any algorithm but the one I described above to determine when to post a new thread.
Part of what was going on at my end was I'd somehow picked up the misconception that we already had three new chapters.
I was setting up the article for chapter 91 with the intent of doing one article for each new chapter because I don't like like dealing with long threads, but it occurred to me to ask whether people have a preference for one, two, or three threads.
Someone else would have to consolidate multiple threads and it might not be possible to split a combined thread, so I'm checking first.