Not a silly idea at all. I try to stay flexible so I keep a couple of full-sized packs with "everything but the kitchen sink", including bags and tent, some water and enough food for 96 plus hours. This is basically (excet for a larger supply of stored water) my bug-in kit packed away ready to travel. But I also keep a light pack that will be for traveling fast with minimum requirements.

I also have three bug out plans. Since I would be evacuating from NYC, auto is the least likely scenario. Boat is second, and on foot/bicycle to our summer house 75 miles north is also a doable option.

This would be an excellent excercise, since all my plans need a lot of refinement.