Yes I did it on my cross bike with 41mm tyres
My superlight Bontrager racelight wheels, I discovered on the saturday, had split 75% of the rear rim so I had an emergency purchase from my LBS of a pair of Mavic Aksium Elite, and then had to spend the day fitting tyres, moving brake pads and changing a chain!
I had decided to go for it and tried to stick with the front group through the town but then lost them on the hill but kept going. The bridleways were good fun and quite challenging in places, the open hills were saturated but the headwind was pretty brutal.
Some descents were too steep, soggy and headwindy for even the MTBs and some descents were too steepy and muddy for me on the CX bike with sh1t brakes and thin tyres but I was pleased to have it
I finished the long route in 3:33 and about 14th finisher which I was quite chuffed with. I was suprised how few CX bikes their were overall, definitely more Full Suspension bikes than CX bikes and I really dont know if I would have been quicker on MTB or not
Overall a really challenging route on a CX, which is why most people went MTB, but a tough and enjoyable day.