I finished Book 5 in the Endless American Dream series during October and I am now digging in to the final book in the series, the penultimate book -- book 11.
It's proving to be a great boon to me to work on the "end" book. I'm adding layers to books 1 to 5, I'm making notes for books 6-9 and book 10, and I'm getting a good idea of how to maneuver my plots going forward.
I'm trying to wrap up book 11 by the end of the year, then I'll start work on Book 6 next year. I have the entire year to work on this series because (ta da!) I have a home for my mystery series for the next few years.
Happy new year, indeed....