Well, that's really an inside joke. When we first married, Bill's grandmother had us back to her house that night after Thanksgiving dinner - Bill called and told her we'd bring some Cold Duck (meaning the wine). She had the pan ready to put the duck in the oven - (generation gap! :) These 3 made me think of that night.
What a lovely image and I smiled at your duck story. I have to say, though, I've never heard of wine being referred to as cold duck. I'd have done the same as your MIL!