Luxury item to carry alcohol and keep it cold

Why does it need to be insulated metal?

I have a Thermos with small 16-ounce volume that is all plastic.

–B.G.–

Check out an Eco Vessel Boulder Triple-Insulated Stainless Steel Water Bottle with Screw Cap

No added weight (and free) would be to freeze the drink in question and store it in the middle of your sleeping bag. For longer transport times, I've wrapped frozen food or drink in the middle of a sleeping bag or bundle of clothing and then put the whole stuff sack in the deep freezer for a few days in advance of the trip. Depending on the weight of the food/drink and the insulation, I can get 12, 24 or sometimes 36 hours of it (2-3 pounds deep in something like a sleeping bag, all pre-chilled).

The thermos Nissan stainless vacuum bottle is awesome. I've used for this purpose on car trips – really works better than any thermos I've tried.

http://www.cabelas.com/product/Thermos-Nissan-Vacuum-Bottles/713342.uts

I use a Hydroflask to transport ice into the backcountry when we're having Dark and Stormies. They have several sizes, and I can get ice cubes to remain rectangular and large for 36 hours.

Put your beverage of choice in a thin-walled bottle. Prop it up against some rocks in a cool stream for a bit before serving. Enjoy cool alcoholic beverage.