Again, with the huge benefit of hindsight, it looks to me like there was unlimited water and at least a few days of food in the cabin, but I really have no idea how often people come by there. Some have suggested starting a smoky fire, maybe with a car tire. Another option would be to leave the family up at the cabin, and have the dad head down to the valley alone at night or very early in the morning to get help. He'd be able to move a lot faster without a four year old in tow.