In my experience this is because too many people(snow players) are connected to the one tower in town. Seems to happen every year on the weekends that have snow.
You aren't wrong.
In this particular case, the Verizon "tower" was completely broken.
What you're talking about is congestion. At worst, you can text just fine, but voice calls will be choppy or get dropped, and may take several tries to get through.
In both of these cases, WiFi calling works wonderfully as long as you have a wire/fiber based connection. That bypasses the towers.
Something I notice which makes the problem worse is the sheer number of people who use the various "Home Internet" offerings from the major carriers. Those suck up a ton of bandwith making it hard to get a word in edgewise. A single video stream is about the same usage as 2,500 voice calls.
I would also suggest a cheap VoIP service. Mine cost less than $50 to set up, plus about $0.85/month and just under a penny a minute. Since we almost never use it for calling, it's always under a buck.
If you do this you really need a UPS for the ONT or cable modem, router and the VoIP adapter.
