It's your call and your strategy, just a thought: if you are in a situation when you need to move quickly some distance on foot, do you really want to carry that much stuff? Most people prefer to keep their BOB fairly compact and only take the real essentials (eg. things you can't efficiently improvise on the spot). It's no good to arrive at your destination all exhausted and out of breath. It might be better to conserve your strength for all the other challenges you'd have to face. Unless you are in terrific shape and do these things on a regular basis I guarantee you hauling a 40kg pack will wear you out in no time.