Powder, a closed cooler will stay frozen for a week. A cooler you open 3 times a day won't last much longer then ice. Best option, pack in a few different coolers, and don't open the ones for later in the week until you are ready to go. Also make sure these coolers are tightly sealed, or it will be gone by mid week.
One other thing we did was pack all the coolers with regular ice, then use a chunk of dry ice in each cooler to help keep the ice and the food cold. But if you are opening the cooler, it will still melt quick. What worked pretty decent is to have one cooler with just ice, regular ice, and dry ice to keep the regular ice frozen. Then take a bag of ice out a day to add to the other coolers. But after trying so many different things with coolers, and dry ice, we just figured out that when possible, a trip to the store every 2-3 days for ice and food for the next couple days. Much less hassle then carrying 5 coolers. Even one trip mid week to restock food, and ice is a much better option.
Sent from my iPhone using Tapatalk