Of course, the way I exceeded it the second time was by rewriting the part of the story I hadn't backed up the first time. Also, I wasn't home at the time.
When I got home, I resyncked and then started a new file. After writing it twice already, writing it a third time was easy, and I'm nearly caught up. And, of course, I think it's better. From now on, when a WordToGo file reaches around 10K words, I'm going to continue in a different file.