Dividing wasn't as bad as I thought it might be. It was time consuming though.
I spun just enough to get everything all tensioned and joined and should finish plying tomorrow. I will probably have a two-ply mini skein when the opposing ply runs out. I don't think it was that much thicker than the rest, but as the other two are relaxing into the ply, that one is continuing to coil up which probably accounts for the difference in length I'm seeing.
For the rest of the Tour, my goals are to finish plying tomorrow, spin all of the samples I have left from the Phat Fiber box I got last year on the Challenge Day, then ply them all. I believe I have six samples left, so spinning them all leaves one per day to ply to finish out the Tour.