I have not been able to make myself purchase a Yeti. A partner has one, and for float trips finds it a bit heavy. Fine for truck camping though. My largest Igloo's can keep ice for up to 12 days in 80 to 90 degree weather and still have about 20% left.
1. Keep them shaded if possible
2. Perhaps a damp towel over each for evaporative cooling
3. Shoot the first person that uses ones cooler as a seat - sprung lids and seals let warm air in
4. Blocks will keep much longer than cubed or crushed, and
5. Put ones ice in a chest freezer at home and take it down to 35 or 40 below before packing
All of you suggestions are good. I haven't used the damp towel but I have put plenty of blankets on my to keep it insulated also.
