Gis a shout when you plan to go . o/suit with light clothing / under-suit will more than suffice.
Do you like mud? it rained over the w/end, and the usual result (in Derbyshire , with a few exceptions, ) is mud. It's good mud tho'!
Only warning : T'owd mans workings have a lot of loose roof. keep to the usual (posted / see reports) routes, until you are happy to judge for yourself how safe aroof is. (see owd git photo bucket jug holes bit!
Beyond that do have fun and enjoy a lovely little system.