5G covers the same area as 4G on a given frequency. They're ostensibly the same technology on the air interface. The original name of 5G was "LTE2" in fact. Carriers are moving to 5G standalone where all voice, text, data are on 5G. In the US, T-Mobile has 5G on their band 71, which is 600MHz, likewise AT&T runs 5G on their 850MHz band. These bands can reach many miles away from a cell site. I regularly have seen a 5G connection to a site 8 miles away from me, for example.
The coverage will be practically the same as 4G, but slightly worse than 3G. (Which was also true for 4G.)
Carriers will likely do a slow roll over the next 5-10 years migrating 4G bands to 5G until only one or two are left on 4G for legacy devices. Not really an if, as much as a when.