Defining your requirement is the first thing. What do you want to do? Are you looking at long-term shelter in place preparations? Bugging out may not be the best option. Bug out? Where are you going to go? Is there a chance your neighborhood will require mandatory evacuation?
We bought a Captains Bed to make room for some of our stuff.
Make sure you can manhandle your bailout bags. A couple of small suitcases, like you would put in the overhead bin on an airplane, may be better than a duffel bag. This is one reason I bought a couple of mini-parachute bags from Coleman's. Make sure it it fits well and you can carry it to the car easily - and it fits in the trunk. A suitcase works as well as a backpack in a lot of situations.
Be ruthless with culling weight.
Cytez has a good idea - offsite storage. Do you live in a floodplain? Rent a storage unit, from a reputable corporation, and keep your bail out supplies there. Make sure it is out of the floodplain. Be sure to include supplies for your dog. I use a re-purposed M5 bag with dog food and such.
Don't forget records; marriage certificate; deeds; car registrations; estate plan, etc.
Here's one idea. This woman dedicated a coat closet to bailout supplies.
The Latter Day Saints have a lot of no-nonsense planning for self-reliance and preparedness. They will talk with you and sell you supplies at their store.
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