In some respects the best neighbors to have at your survival retreat are none. The fewer people that are in an area the less likely an armed group of looters will be checking the area out. Looters and other parasitic creatures will prey on those that have neither the knowledge, weapons or will power to defend themselves. If the area that your survival retreat is situated in has large numbers of unprepared people the changes of looters attracted to your retreat will be greater.
Although an area where there are multiple survival retreats linked together with wired communications may be able to offer each other mutual defensive support in case a massive band of looters happens to fall upon the area. This plan may be worth consideration.