The problem of anons being too isolated is a problem, but what is your solution?
You are an user only on an imageboard. When you go to meetings of your local book club (most universities, and even community colleges, have one that is open to the public if there are no others), gun club, political party, PTA, or anything else, you are not anonymous - and neither are the people you meet. You know many of their thoughts, opinions, tendencies, affiliations, friendships, and so on, and thus you know who you can trust deeply, who you can be mutually dependent on/allied with, who to watch for flakiness, and who to never give the chance to stab you in the back. Simply by living a non-anonymous life (I'm saying go out and meet people, lots of them, whether you like them or not, because meeting people = screening people) you are enhancing your physical, flesh-and-blood network. You are laying the groundwork for a society, and a society is all that can survive in post-collapse America.
Societies in general are marked by the sharing of:
Information: Teaching others what you know, training them to do what you can do, and you learning from them in return. This ensures the continuance of the society indefinitely.
Resources: Whether by throwing goods into a communal pile, giving them as needed, or a more mercantile arrangement, resources must flow within a society to keep it running. The nature of an economy is up to the society to determine, but regardless of group inclinations, an economy will always exist.
Responsibilities: You cannot be awake 24/7, you cannot guard from all angles 24/7, and you cannot do everything on your own. You will need someone to stand watch while you sleep, to farm while you fix things, to run cabling while you fish, and so on.
All of these are merely manifestations of the same idea: We cannot be everywhere at once. Your chosen society is the extension of yourself. You can probably survive without a society, and a society without you - for a time. But the nature of the Aryan is not one of survival, it is one of civilization, and civilization is an inherently collective endeavor.
Thus we must by absolute necessity - not merely of biology but also and especially of our transcendental consciousness - form societies in order to procure survival (short-term) and the sustainability thereof (long-term) for the individual, as well as creation (production of food and other goods, invention, construction, theorizing, all short-term) and prosperity (long-term continued creation taken above and beyond the limits of our current understanding and capabilities - in short, futurism) for the society.
tl;dr If you want anything good and white to survive the coming collapse, you need to form massive, in-person social networks; friends, friends of friends, friends of friends of friends, and so on. You need to get involved in your local community, find out where the problems are, and be ready to fix them when the time comes. You need to build a sturdy, well-rounded society with doctors, soldiers, farmers, engineers, and everything else necessary accounted for and trusted by you. No, they don't all need to live in an underground bunker until the day arrives - you don't even need to be on the same block. Just get to know people relatively nearby, say within an hour's drive or so, because those are more likely to be the people you're stuck with in the first weeks/months of anarchy, and thus the ones you need to know you can depend on.