I also insulated the bottom of mine and it will keep a drink cold for at least an hr. I it starts out semi frozen it will stay cold for 2 to 3 hrs.
Beer goes in the cooler, and water or gatoraide goes in the cup holders. If they start off slightly frozen they will still be cold for that long. However that doesnt mean they last that long.Your not drinkin fast enough if your drink is in there for 1-3 hours lol........