I set up my 165Qt Igloo with dry ice as an experiment during a one week fishing trip with my brother. I set up partitions in the cooler to separate it into 3 sections. In section 1 I added frozen food in reverse order of intended use and topped it with dry ice wrapped heavily in newspaper. Section 2 got a dry ice wrapped in newspaper on the bottom followed by a 1 gallon frozen water bottle and some non-frozen food including a cantelope. Section 3 got wrapped dry ice on the bottom followed by cold, non-frozen food.
In the end, I thought the dry ice did very well, but at a cost. I spent about $30 on dry ice and most items fared well. I did have some non-frozen food that was ruined in the freeze like celery. I also had that cantelope that didn't freeze, but became carbonated from the carbon dioxide in the sealed cooler. It took me a while to identify what was wrong with the cantelope since it tasted normal and the texture was normal, but the fizz in my mouth gave it away. It was actually kind of refreshing!
Most of the food did well, but I considered the cost as excessive for the gain. Since then, I've added a second fridge and rarely need a cooler.