I bag my own groceries. I put all the cold stuff together. Canned goods together. Bananas and fruit together, toothpaste and toilet paper together and so on. It's easier to put the groceries away when you get home. You use less bags. You can also bring your own bags. Some stores give credit for using returned grocery bags.
This is a page about keeping groceries cold. Sometimes we may travel quite a distance when grocery shopping.