I carry all that stuff in the knapsack (always within arm's reach)
but also a small fanny pack with

cell phone and spare battery
matches and a couple candles
leatherman
chapstick
whistle on lanyard
spare keys (house, car & airplane)

Don't laugh about the keys! I've gotten stuck out of town without
the house keys. Managed to get home but all the keys and the car
were at the hangar more than 30 miles away and no neighbors home.

Once is all it takes.