The point that I was trying to make is that a 72 hr plus kit contains what............more food, extra batteries, change of clothes or additional clothes? the 72 hr kit has everything you need to survive for 72 hrs, including water if possible. To extend this what do you need.......more consumables. You won't be able to carry more water unless you have alternate transportation so you are going to have to find it along the way. Go backpacking meals and you get light albeit expensive. Toss in an appropriate sleeping bag and bivy/tent. You don't need to go 80 lbs, but what is the real delta if you go light on food and don't plus up the water?