Don't forget, he is committed to a Cinder Spires book first, or at least concurrently. He should be well into Olympian Affair now. Though there have been posts they may be being written simultaneously.
Yes, Jim said something about writing both books concurrently. It's something he's never done before. I'd be surprised if we got the next Dresden book before late 2022 and it wouldn't surprise me at all if it wasn't until sometime in 2023.
Having said that, Jim made an appearance at Dragon Con over the weekend. He did at least two panels there. You know someone must have asked Jim how this new writing experience is going. In other words, asking how far along Jim is with both books. Back when Jim was having all kinds of personal problems which slowed down his writing on what became PT and BG, he didn't really give specific answers to that type of question. He'd mention deadlines or hoped for finish dates but not much else. If you go back further in time, Jim has been more forthcoming about his writing progress of various Dresden Files books. In a few days, when a video or two of Jim at Dragon Con 2021 is posted to YouTube, I'll be interested in seeing how Jim answers such a question or if he just comes out himself and tells us how this new writing method is working for him. Even if he said something like like, "I'm halfway finished with both books", that would tell us something.
So, I recommend checking YouTube over the next few days to see when a video featuring Jim is posted, to see if we can get any solid clues about his writing progress on Twelve Months. We can always hope that my gut feelings about when to expect the next DF novel are too pessimistic and Jim is much closer to finishing than I am guessing he is.
