Don’t put too much faith in the manufacturers estimates, when it comes to how many days worth of food their products claim. In a very short duration event; the estimates may be ball park accurate. In a longer term event; one must consider their own higher calorie consumption rate. Collecting food, water, patrolling, security. And all the labor expended to perform these tasks without modern convenience. As for “stockpiling”? I say stack it to the rafters. But be realistic, and understand, that at some point you’re going to have to shift from mere consumption; to production.