Recommended 2:1 ice-to-contents ratio and to open the lid only when you're needed, the less, the better to minimize heat transfer
between cooler inside and outside. It will be better if you put the cooler in the freezer to pre-cool them before you fill them.
When the cooler in outside FULL with ice, will keep 5 to 7 days under 77℉(25℃). About 100℉(37℃), ice will stay about 3days.