Instead of writing today, I started outlining chapters that happen after the current “end”. This should be a useful activity if I either need to extend the current novel with this material, or if I ever want to write a sequel. Having an outline of this will help me decide if extending the story is the better way to finish the novel.
I didn’t use an outline for what I’ve written so far, and I suspect that accounts for a lot of the problems I’ve been having, such as the story not being long enough, or having big chunks of stuff I needed to throw away during editing. Hopefully outlining will work better for me next time (either that, or my subconscious has figured out a new form of stealth-procrastination).