You may be able to talk them into holding it for you, and picking it up when you're done at MK. We did this a few months ago. You have to show your receipt to the hostess, who then marks it that you've received your cup when they give it to you. As long as you keep your 'clean' receipt, you might be okay. I don't remember WHY we did this (possibly doing the same thing you're doing), but we just explained that we weren't able to carry it with us, and they had no problem with it.