If you decide to go to Brockholes, I hope you have a lovely day with or without Cookie Monster
I find shows a useful way of developing my hamster knowledge and educating members of the public about the wonderful world of hamsters.
I am lucky enough to be able to drive, but have had several people transport my babies by train. Despite being young, they all coped well with the journeys and stayed asleep snuggled up for the duration. If you decide to take Cookie Monster, I would suggest putting him in a secure container with some food, a chew/tube and a moisture source such as cucumber. To help him settle, put some of his substrate and bedding from his cage into the carrier too, or let him play in the carrier so it carries his scent. Most of my hamsters, both Syrian and Chinese, settle down with movement, although they may be nosey and active when they first go into their carriers/show pens. I had one Syrian hamster who demanded attention from anyone and everyone, and I would cover her carrier (it was like LRP's) with a folded teatowel so she wouldn't get overexcited when we went to the vet (on one memorable occasion we nipped into the bank near the vet en route - Bella enjoyed that, cheeky girl!).
Whether or not you decide to take Cookie Monster is your decision as you know best how he is likely to cope with his outing