Well it will be based on cellular connectivity, so guess will have to go by how good your cell signal is. I'm sure there are area's with no cell service that won't get 5G.
I work in the satellite industry, and part of the 5G upgrade is that they are taking a large chunk of our frequency spectrum for it (also why UHF TV channels have been moved around if you still get TV over the air). They made their case to the FCC that them getting the spectrum would be more beneficial to the people as they would be able to provide high speed internet to rural area's. Of course they said this to make their case, not sure how much effort will be put in to extremely rural areas... but if you get cell signal, they will be able to upgrade the towers to 5G. They particularly wanted our spectrum since those frequencies travel further, so you will have to see.