I'll have a look later for you, gotta get ready for work!! The problem with a caravan holiday when you go by train is how do you take the kids and luggage??! I don't drive either and it might just be doable with 1 child!!
Can you perhaps look up local things to do, or things that are an hour away from you, and perhaps book a BnB for 1 or 2 nights? That way you won't need too much stuff and it'll be a mini break so to speak.