I left close to 7am and whilst I wasn't really "in a group" there were a lot of riders around, which probably helped. But after the first feedstop I was either alone, or with one or two riders in view, for the most of the ride. With the exception of an hour or so from the second feedstop when I tagged along with a small group.
I think that over that distance, terrain, and with so many feedstops people must have got pretty spread out.
Roll on next year indeed!