I like the idea. Obviously, as I put on several 200km one-way Perms (Holyhead-Poynton, Poynton-Holyhead, Stalybridge-Scarborough).
I would want to book my bike place on the train - in fact I think it would be mandatory - but it would be an extra incentive to getting a shift on. What sort of numbers of bikes do those trains take, and how many trains per hour? For the Scarborough-Stalybridge train, it's 3 bikes on an hourly service, so it would take days to return a Calendar event to base.