Did not occur to me that you were talking about a new coat when you said Dryrob. Sounds very like a very handy piece of gear by the way you describe it.. The definition that popped up on my search was a dry Rob Roy cocktail. Which also sounded pretty good. Never had one, so was not sure how they went with the chocolates you got. Seems like a good way to start things off.
Being a card carrying temperance member I wouldn't know either.
It was described to me as a portable wardrobe you wear and get changed in!! I must point out at this point that I don't usually get dressed or undressed in a wardrobe !