Three to five days, realistically.

That’s the real answer, assuming you’re using a decent rotomolded cooler (Yeti, RTIC, Pelican, etc.) and not opening it every hour. The marketing wants you to believe a week. The truth is closer to three days in 90-degree heat, maybe five if you do everything right.

The biggest variable is not the cooler brand—it’s how much ice you start with, how cold your contents are, and how often you open the lid. A pre-chilled cooler with a high ice-to-contents ratio and block ice will crush a warm cooler with a bunch of Cubans in it that you open for drinks every 15 minutes. Also, shade vs. direct sun matters more than you think.

My rule of thumb: plan for three days of solid ice retention. If you get four or five, bonus. If you need longer, bring a second cooler or dry ice. High-end coolers are amazing, but they’re not magic. They just slow down the inevitable.

Plan for three days and you’ll be thrilled with anything more.