Finding a location by IP address is not always reliable. The first result when googling my IP address yields a city 1,000 miles away (other results have the correct city). Then, knowing the first digit of a street address gets you a range of addresses that can represent anywhere from 1 to hundreds of homes. It's theoretically possible to get a specific address from this method but it's unlikely and not reliable.

The point of the article is that you could essentially get the exact address house address from just the IP of a Comcast customer

Right, and my point is that you essentially can't. For my address the best you could do is narrow it down to ~30 or so homes that share the same first digit as my address. For this to work you have to:

(1) Have the IP address return the right location

(2) Not have duplicate street names in that location

(3) Have a single digit address OR be the only home starting with that number

That's going to be a pretty rare combo. Probably less than 1%.

They'll be able to narrow it down to 10-30 homes, but from there they can see who owns those homes, research those people on social media etc., and determine who their likely target is.