Block ice lasts longer than cube ice. But the commercially available block ice might be too large or cumbersome for your cooler. The solution: Make your own longer lasting ice. The trick is to choose a container that has tapered sides. This will ease getting the ice out. Also, using a flexible plastic container helps too. Containers that have worked for me are Cool Whip containers, some Tupperware containers, and plastic souvenir cups. I suggest start making your ice at least three days before your trip.