Re: Most people...
There's essentially no coverage at the Mountain Fastness (you can get sometimes get a decent signal in some parts of the grounds), so I got a used AT&T microcell unit off eBay. (My wife has AT&T; I use an MVNO which resells AT&T service.) Hooked it up to our router - we have fiber Internet service - went to the AT&T site, registered it, and presto: excellent service for anyone with AT&T service whom we add to the device, as long as the power and Internet are up.1 It needs to be sitting near a window so it can get a GPS signal, but that's not a problem.
Obviously this requires a carrier that allows microcells and a reasonable Internet connection for backhaul, but it's worked well for us.
1Nearly always, despite the rural location.