The Two Strategies
At a high level, there are two different strategies that one can take when trying to survive aggressors when TEOTWAWKI rolls around.
On one hand, you can lay low and try to remain unnoticed/hidden, or at least be so elusive that an aggressor can't mount a direct attack against you. You operate from concealment and have, generally, a run/hide mentality when trouble runs around. If you engage the enemy, it's going to be using sniper or guerrilla tactics; you won't survive a standup fight. But mostly, you hunker down, stay hidden and survive.
On the other hand, you can maintain an open defensive posture, where you directly confront aggressors. In this case, you would have things like open patrols, check points and other obvious defensive measures. Your organization would have ability to project obvious power and control within your area of operations, allowing you to maintain some level of law/order. When trouble comes around, you stand up and fight.
These two different strategies go back to the natural instincts of fight versus flight--sometimes, it makes sense to stand and fight, other times it makes sense to run and hide. You can see these play out in conflicts today and throughout history--the U.S. against insurgents/Al Queda, the DEA against drug smugglers, Anne Frank and the Nazis and so on.
This is the defensive posture we'd all like to take -- no one wants to live in secrecy and in constant fear of attack or discovery. You want to stand up for yourself, your family and what is yours. Unfortunately, it takes a good amount of power to be able to live this way. You've got to be strong enough to scare away potential attackers and defeat any who are brave enough to test their luck. That means that you need manpower and firepower.
A small survival group is not going to be able to take this stance--you'd need a larger group--a neighborhood or a small town, most likely. The community would form some kind of neighborhood watch or town militia for mutual defense, probably with the aid of intact law enforcement or military personnel. With the bodies and some fire power, a community could defend their homes and maintain order.
In survival fiction, the towns in One Second After and the neighborhood in Lights Out take an open defense posture. The town in Jericho does, too.
In a collapse scenario, I think this would be the response of most communities. When a larger community breaks down (nation, state, city, etc.), it's a somewhat natural transition to fall back onto a more immediate community--the people next door and across the street. There's huge advantages to community--it's civilization and safety. A sustainable community would provide the best quality of life, post-TEOTWAWKI--but it would have to be sustainable. That means things like local water, food, probably some kind of fuel, and decent people who don't already hate each other.
Problems come when things like food and water run out, internal strife tears the community apart, the community runs into an aggressor they can't contend with, or if disaster renders the community unlivable. How fast that will happen is going to vary wildly based on your location.
The Stealth Approach
If you can't beat aggressors in a stand-up fight, then it's run and hide or become subject to the aggressor's will. In general, this survival strategy means, surprise, a lot of hiding out and going unnoticed. If fighting must be done, it's using sniper and guerrilla tactics. If movement must be done, its probably at night or at least in thick cover and well camouflaged. If your hide site is located and threatened by a superior force, then you bug out to somewhere safe, maybe with a sniper or guerrilla attack to slow the baddies down and allow you some breathing room. You get the picture.
This kind of existence is difficult to sustain long term. Survival is hard enough without having to worry about doing everything in secrecy. For example, how do you farm or raise a vegetable garden in secrecy? How do you cook or keep from freezing to death without drawing attention? How do you deal with waste? Now compound these problems with multiple families. Very difficult.
Living way out in the hinter-boonies would offer some advantages, but in a collapse scenario, every remote farmhouse or cabin will have a good number of visitors looking for a place to hole up or scavenge. If there's a road, people will find it. And yes, you can make a house look abandoned or burnt out, but desperate and curious people will still check it out. Crowds certainly will be smaller way out in the middle of nowhere, but your chances of having backup from neighbors/the community are also going to be lower. If your group can't deal with whoever comes knocking, then you've got a problem.
A real hide site is going to be, well, really difficult for anyone to find. Hard to access and hidden. In a rural setting, a remote and well-camouflaged camp that's not accessible by road; maybe a cave or excavated hide. In a more populated setting, a concealed bunker or hidden safe room. Spider holes and hideouts, that kind of thing.
As mentioned, a hide is going to be very difficult to sustain long term, so it will probably need to be a temporary situation. You will need to emerge and resupply eventually, whether that is through pre positioned caches, barter, hunting/gathering, farming or relocating to another area entirely.
In survival fiction, the man and his son in The Road generally follow a stealthy approach to survival, avoiding contact and hiding when trouble comes around. They have it best when they find the concealed and well-stocked underground bunker. In Patriots, the Group adopts this strategy when confronted by the evil U.N./black helicopter invaders and retreat to their wilderness hide and begin their guerrilla war. In the Survivalist series, John Rourke's concealed retreat/cave complex is an elaborate and well-stocked hide.
It would be narrow-minded to only think through one strategy or the other. An open, community or large group-based approach to defense and security is going to be preferential for most of us, but it may or may not work out. The back-up plan in that case would be a stealthy approach--if the community is done for, you bug out to somewhere safe and hunker down until things blow over.
In more common prepper terms, if your local neighborhood/community is a viable option, then an open, community based approach may make sense. If that fails, then you still have the opportunity to bug out and hide. Consider and plan for either possibility and I think you'll be better off.