I decided to change from brown bagging it when I go to all day quilt classes and found this kit online. It's called the Zippity-Do-Done insulated lunchbox tote. Kit includes instructions, preprinted insulated batting, handle strapping, plastic interior base, and a white Zippity-Do-Done zipper. The kits are available in different colors. Here's the finished tote!
I made one change to the pattern. The white fabric you see on both sides of the zipper is not in the pattern, the zipper is rather wide and I thought I would cover the excess zipper tape with a pretty fabric. I like how it turned out!