Yes. The United States and Canada still have vast distances where the cellular systems only exist along the “interstate” (four lane, high speed, roadways similar to Germany’s autobahns). If you look at cellular coverage maps on the carrier sites, they tend to be “overly optimistic” fir obvious reasons. As of late, there seem to be more instances of real estate developers buying tracts if land in very rural and agricultural areas and putting in divisions and “council flats” as you call them. I guess these appeal to those who prefer to escape the congested inner city life.
I think you’re wise to do this. Some of my neighbors and I are doing same. Just back-up, just in case. We’re using GMRS radios and have a very strong repeater in town. No trouble going basement to basement, simplex, on low power settings, but we’re only going down the street from each other. Someone suggested you could relay, talk to whom you can reach, let them pass on to whom they can reach. Should work okay. In my case, we have <ten houses on a circle surrounded by conservation land so we’re pretty remote by area standards. (Seen hunters stumble into my yard, clearly lost.) In an emergency, coms are vital. Hats off to you and your 'hood.
Use a good cb radios
The snag with Cb is just antennas. We don’t have this if all else fails approach here in the UK but if I read your need right, you need reliable as and effective local comms between people sort of know to each other or known to others you know. UHF with long shelf life batteries and empty packs seem the most useful and if these are self funded not too expensive. Recharging once in a long period of no use could be a problem so dry batteries make sense. You seem to have access to this kit so the KISS system is the one to go for.
Raynet uk can handle all types of emergency communication in emergencies. Represented throughout UK by licenced and trained Hams.