I have been experimenting with a BOB/GHB bag in my vehicle for the last two or three years. It's completely empty.....

I travel for work (25 years on the road) routinely thru several biomes and in all 4 seasons, and ending up at hotels several nights a week. Traveling from river and ravine country in SW Wisconsin to the boreal forests of the northern MN/Canada border and thru the northern boglands over to the plains and prairies of North Dakota often on secondary roads, no one bag would work. My personal travels aren't too much different, except I'm in my truck and I end up in the woods.

Rather than re-doing my bag for each biome, scenario, and activity, I carry it empty with a 20 gallon tote in my vehicle with everything I need for water, repairs, fire, first aid, shelter, cooking, and emergency food for any biome, any season, walking or driving (OK, I admit that not everything fits in the tote, but I'm working on it). I also carry season-appropriate extra clothing and extra hiking boots.

The advantages as I see them are that I don't have to choose in advance, I just pack what I need on the spot. I can easily access the supplies if I want to stop along the way somewhere, and I can quickly pack the bag if I have to walk in a remote area for any reason including recreational .

When I change vehicles for a backwoods trip, I just toss the tote and empty backpack into the truck with my regular camping/hunting gear. Everything gets handled and used on a regular basis, so no surprises. Not having to choose in advance between a small portable kit and a 'truck kit' has been the best of both worlds for me.