Update
So first I rang Arriva Trains Wales Customer Service. They couldn't help so someone from their head office has just called me
A long and painful conversation. Basically, unless it's a folder, you're stuffed. They will take a folder on the bus, but a non-folder is impossible. So I said "what are you proposing for those people who are stranded in Llandudno with no means to get home?" Tough, basically
I'm not going to change the date of the ride, there doesn't seem much point and folk have paid non-refundable accommodation too. If you're stopping over, you need a folder or be prepared to ride to Chester (a very flat ride, that's probably what I will do)
Unfortunately I am away on business for three weeks before the ride. I don't have time to try to organise something like a minibus or similar. Hopefully someone can offer to organise this and then it becomes a workable solution
Pain in the 'arris this