That's the rub, isn't it?
For me, a 500km in the last week of December is too great. 100km would be- if it was snowing in the morning. I don't think the Dean should be banned, but the snowy one should have been cancelled- how would the organisers NOT have been liable if something had happened to the few brave foolhardy souls who set out?
We all (surely) tut at teenagers in trainers heading up mountains in changeable weather forcing the mountain rescue bods to go out after them. People drowning in frozen lakes having gone out after their dogs. Firemen dying because kids lit a campfire which got out hand.
It's all fun and games and macho bravery until someone breaks a pelvis. There's a hefty tally of cyclists who took a chance and broke collarbones and hips, and will we still be OK with this ride on the calendar when someone dies?
Of course that's hyperbole and really really (really) unlikely, but for me, this ride crosses the fine line between audacity and stupidity. A group of mates doing a perm and making a decision on the morning of the ride is not the same as a calendar event under the umbrella of Audax UK.
Risk isn't the same for each individual. I've walked my bike down the Gospel Pass over ice on the Gospel Pass 100 as a few others confidently and safely just rode over the ice. I'm sure I'd have ended up in A&E if I tried.
Some drown in frozen lakes trying too rescue their pets, meanwhile others go diving into icy lakes just for fun without any problems, just as some go swimming in lakes where if I tried that, I'd not expect to come out if alive, unless I built myself up to be able to do it.
IIRC the Dean had a get out clause, that if anyone ride the following week, brevets were accepted. I think that almost everyone deciding not to ride negates the need for the event being cancelled. Those who did start (and finish) knew what they were up against. The main reason I didn't ride was because if it did get unrideable, it would have been expensive staying in a hotel and been a hassle getting back home. I had to be at work on the Monday and that might have been challenging or very expensive if it got really bad. Otherwise I'd have had a crack just for the fun and would have pulled myself out if it got nasty.
I'd ride an event where a rider has died on a previous event. PBP for starters. I don't do macho bravery. I think that the kind f person who does will come unstuck one way or another anyway.
I think you demonstrate my other point well. It's just too daunting to take on lightly. It doesn't look so bad now, when the weather isn't oppressive and you have some fitness (if you're lucky! I've got to build some up again) but once you lose some fitness, you get a bit slower and start going outside and think, "Bugger me! It's freezing! Sod doing 500k for a game of soldiers!" it starts dawning upon you that deciding whether to do a 500 or not needs consideration. this often makes you an avid weather watcher, just as it does with any significant ride, so you can plan kit etc. (or even whether to ride or not)
I suggest the danger is more imagined than real.
This reminds me of when I stayed in Ambleside YH one Christmas to do some mountain biking. I booked in advance but it snowed so I abandoned my ambitious plan to ride the High Street and just bimbled around a bit on my mountain bike. Still did some off road but ended up walking a lot (and got passed by mountain bikers who were confidently riding over the icy path I was walking along precariously)
A rock climber was also staying and we got chatting. He thought I was very brave mountain biking and didn't think that he was especially brave rock climbing.
It wasn't me who downed a bottle of wine the following night after a scary experience....