You should be able to get 9 person-days of food (c. 35,000 kcals) into a standard bearvault, and with the first night's food separate, that covers 10 days. Make sure you let the air out of all packets and squash hard...
e.g. 40 tortillas (there's a size that perfectly fits the diameter of a bearvault), 27 granola bars, 1lb cheese, 10 snickers, 3lbs spaghetti or instant potato, 1 quart olive oil (=9000 calories!), 9 packet sauces, one squeezy jam, 1 salami, 2 lbs skittles & M&Ms (poured in loose at the end to fill all the gaps).
