Last year on a hunting trip to Maine in October a member of our group had a new "YETTI" cooler. He had been out there beyond electric power for about two weeks and his cooler still had about 90% of th...
Ambient temp of only 75 degrees? Those things would only last 3 days max out here in AZ in 110 degrees, and the air temp inside would never be food safe temp.
I would save those for drinks and get an Engel or other electric fridge freezer that will hold double the food since you don't waste the space with ice.......and your sandwiches stay dry and at a safe temp. I use mine with a deep cycle and solar....as long as the sun shines it will run for years.