A town park with white geese floating around a pond just won't do it for you. You need a remote, windswept beach, with big waves crashing down on the shoreline in front of the dunes, or a steep mountainside high above a big valley, miles from the nearest road. Or, you'll be canoeing a river or driving a dirt road deep into the wilds. This is when you want a picnic basket that will keep your food and drink cold not just for a couple of hours, but for the whole day. And, you'll want a basket big enough to hold enough food and drink to sustain you for most of the day—which means something that's easy to carry long distances. This is when you want a large cooler bag with super-strong insulative properties—thick walls, secure closures—that you can throw over a shoulder before you head off. Bonus: You can use such a bag at home to keep drinks cold during backyard parties.