Our approach to sea-steading has been coastal nomadics, emphasizing archipelagos (island chains).
The 'Inside Passage' of the Pacific NW (aka BC / SE AK coast) is temperate (not as sweet as HI, but no frigid wasteland, either). It's boreal ecosystem is largely intact allowing full subsistence foraging (it supported extremely affluent indigenous cultures for millenia). It's remote enough that 'social distance' is easy to achieve (we can actually 'disappear' indefinitely along 900 miles of archipelagos), and law enforcement (re potential anti-foraging laws) is expensive and undermanned. Harbor/shelter every few miles, especially for shoal draft vessels. 97% of SE AK is designated public national forest (this land was made for you and me!).
In short, it's an attractive area for sea-steaders who aren't blue-water oriented.
I agree with Jay's comment that the transitional times will be the most dangerous. What authority remains will tend toward martial law and clamp down on 'looters' and 'hoarders', as prudent foragers are often labeled, even in less trying times. Mobility, flexibility and opportunities to go outlaw (having a back door), I believe, will be essential to viability. To me, archipelagos are 'tangled banks' along the interface of land and sea.
Come on up; the water is fine! (and we would love the community!)
PS. If you haven't read it, Ursula K LeGuin's A Wizard of Earthsea is set amongst archipelagos and gives glimpses of a raft-based, sea-steading community. AND it's a great story, to boot.