Good suggestion with the hardware/feed store concept. As a thought exercise, I'll put this to several folks for discussion and see what we come up with.

I have all kinds of practical questions….
• How would a cache be funded?
• What size group are we talking about?
• How many folks would need to make 'donations' to support a group?
• Do we pool from our personal foodstuffs or buy extra?

When it comes to medical needs, we have your everyday sort of thing; illnesses, fevers, broken limbs, viruses; and then you have the more dire needs such as severed limbs, head traumas, and maybe the odd bullet wound.

Therefore, you’d have to have medical folks that were qualified to deal with the above that were part of your “group” and they’d have to have access to the necessary supplies (most could be stockpiled, excepting plasma and some meds).
I don’t know much about religious groups that have tried to make their own community, such as “Yearning For Zion” group in Texas. Anyone know how they were set up for medical needs, assuming they did more than just prayed for their injured? (Of course, they are already at their “bug out” location so transportation and warehouse issues would not be endemic to their cause, unless they had to relocate.

While I have enjoyed fictionalized stories of possible scenarios, I wondered about the logistics of feeding small armies and getting their supplies from place to place without detection or confiscation.

A great book (non-fiction) for logistics in wartime is “Moving Mountains: Lessons in Leadership and Logistics from the Gulf War” by William G. Pagonis. It really lays down the needs of an army that is often overlooked by folks just interested in the battle aspect.
Until then, Cheers.