I expect Armstrong's decision had other factors, as well:
(1) zero state income taxes on personal income
(2) Republican/minimal government
(3) Year-round warm and sunny
(4) Easy access via air to foreign countries.
(5) Excellent, accessible medical
Being able to afford food and private armed guards probably weren't his highest concerns.
In retrospect, I didn't - personally - make the best choices. I thought "small town safety" and "agriculture" because I was expecting TEOTWAWKI to look more like "Zombie Apocalypse" (economic) and NOT "Invasion of the Body Snatchers" (totalitarian/communist/fascist government).
If I had it to do over, I would choose a lot of things differently. I remember visiting Florida and doing a statewide TEOTWAWKI planning tour (with a prepper friend who had already chosen agricultural Florida to escape the Northeast) around 2005. At the time, I didn't like Florida because too many people and too many mosquitos and "too flat" and generally "not impoverished enough". I later travelled with this friend and some of his other acquaintances to check out S America.
The elderly pensioners aren't that much of a problem as many/most have enough money to only keep Florida as a winter/vacation home. And, certainly, elders are not that likey to be rioting violently in the street.
In all, I wish I'd chosen Florida a long time ago. Most of my other choices didn't turn out that optimally - again, mostly because I was wasn't expecting the "Invasion of the Body Snatchers" plotline we now find ourselves in.
Being "off the grid" / food self-sufficient isn't helpful, at all, in the current script. Maybe in a later chapter, but not now. And to get to a later chapter, you first need to survive the current and upcoming chapters. Being mobile with a strong, low tax Republican government is, imo, vastly more important ...at least at the moment. Again, IMO, and at this time.
P.S., I just added #5: medical. This includes a lot of things beyond mere medical, but when I was younger I didn't concern myself with things which afflict older people more than younger. Once upon a time, as you know, I owned remote property. As TEOTWAWKI is playing out, it doesn't matter what would be nice in end-game...if you can't make it to end-game. All in all, I am coming around to a small place in Florida as a pretty good way to remain safe yet mobile during these very early innings.