Over the weekend I weighed the skein/knit another row/weighed the skein. If my math is to be trusted, I have three more rows to knit before I start the ruffle.
Suddenly I'm all excited and focused again on plowing through this giant shawl. Even though I have nearly an entire skein of yarn still to knit. Even though the ruffle is going to be miles of stockinette. Even though I'm still not sure how much yarn I should leave for the bind off -- though at least with that I'm relatively sure that ~3x weight of 1 round of ruffle should do it.