No need for any dry ice. Freeze it all rock hard in your own freezer. Zip lock anything that might leak. Fill all the space with rock hard frozen foods just before you leave for the airport. Buy extra inexpensive stuff for filling space. Smoked sausage, frozen corn, hot dogs stuff that you can always use for your family at home or on the boat with this crew. We always leave the house with one cooler of frozen stuff we want to have. An igloo duct taped works for us with a small roll thrown in the igloo incase it must be retaped. A taped igloo full of fully frozen material will last for many days. No ice, no dry ice, always full, everything goes in frozen. You can never have too many appetizers and bits for grilling on a boat. It was once easy to sell the empty igloo on the dock when you returned for a profit. We use the igloo for ice during many trips. The empty igloo is great to stuff the wet and dirtiest stuff in for the return trip home.