Didn't take part in the end. I somehow strained my left quadricep tendon a little on the Wednesday (maybe the saddle was in slightly the wrong position?), and didn't want to strain it further by taking part in an event which I wasn't pacing myself.
As it turned out, it was completely fine by the Saturday, and I had a great road ride of about 60km. But I erred on the side of caution.
I felt that I'd done my bit - helped the organiser out by identifying some bits that needed to be rerouted due to ice and new forest gravel and I rode it all anyway.
And I got a nice 120km road ride in on Monday too.