Have you already seen the city results? eg: New York, NY
In NY I'd be looking at Verizon, RCN or Spectrum. Keep in mind that the program automatically does all of the ranking and some smaller, less known companies who aren't ISPs may be listed. These lists aren't human curated. If you hover over the 2nd spectrum listing you'll also find that's for spectrum business, name is being truncated.
I'll start logging postal codes and latitude longitude (as detected from the IP and MaxmindDB) and see if we get more interesting details. First a database structure change would need to happen and taking into account the size of my databases it will have to be planned. I have other proposed DB structure changes that I'd like to take care of that will really speed up certain queries. I'll look at adding this and as well as other fields at the same time.