BOB = however long it takes to get there + safety margin

Before I relocated back to what would have been my BOL under normal circumstances, BOB had 5 days of food, the ditch kit one day. That assumes breakfast, some grazing during the day, and a meal at night before bed, but not any supplementation. There is a tote without about a month of food in it that would have gone in the car, but if I had to walk I wouldn't have shlepped it with me.

As for water, I've got five quarts in my gear, I'd like to add another three. And get two of them into my vest rather than just one.