Actually, Alaska Airlines is quite accomodating to folks bringing frozen goods back from Alaska. Fishermen, hunters, and other tourists come up here all summer, and take back frozen fish and game. Down in Seward or Homer, there are business that will vacume seal and freeze your fresh caught salmon or halibut. You can buy a wax cardboard frozen food box and check it as baggage. I'm sure a box of plain old ice would be just fine.