Does anybody actually need, or use an ice box cooler and depend on it holding ice for 14 days?
For even 7 days for that matter?
It would seem to me, based on reading O.J. and this forum, that most folks who undertake overland travel beyond 3 or 4 days use an Engel or ARB 12V fridge.
I use a Yeti 45, but I know I'm only good for a maximum of about 4 days, both in terms of ice melt, and overall food and drink capacity of the cooler along with the ice to cool it.
The downside to a lot of the ice box tests online and elsewhere is that the testers are prone to filling the ice box full of ice for their test, which is certainly one way of testing a cooler, but doesn't reflect the fact that for the overlander, a more realistic test would be to fill the ice box with 4 or 5 days worth of FOOD and drink, and THEN fill the rest of the box with ice.
I suspect the "ice-life" numbers would drop precipitously in such a real-life test.
Paying big bucks for a super-cooler in order to get more than 4 or 5 days worth of "cool" with ice seems to offer a rapidly diminishing set of returns, as there reaches a point (5 days?) where a 12V fridge becomes the only realistic option.
(the above references overland travel, the kind where your location precludes you from popping into a gas station for a bag of ice, it also presumes that you've got a power solution for your 12V fridge, either by day long driving, solar, or something else).