Adding the location would make the most sense, you would think the seller, wanting to make some money, would practice a little salesmanship. Let's see if this will work, as the idea may seem feasible in the UK, it would be unbelievably unmanageable in the US.
Let us take your example, Tyne and Wear & County Durham. 1200 square miles, give or take, population of 1.5 million. Compare that to Chicago & Cook County, 1600 square miles, population of 5.2 million. Cook county is one out of 102 counties in Illinois, and there are 3,140 counties in the US. At 50 sub sections per page that would give us 60 pages in the US section. If we could consolidate on the average of 10 counties together it would bring us down to only 6 pages. That would give on the average 10 times the area per US sub forum.
The UK consists of 94,500 square miles, population of 61.6 million. The US consists of 3.7 million square miles, with a population of 306.6 million. mental math gives me around 35 times the area for the US, and 5 times the population. Since our biggest concern throughout this topic had been travel distance, it would make the most sense to use the area figures.
Take whatever you envision for the UK section, and multiply it by 35 for the US section. By all rights, since distance seems to be the main concern, for a single UK section the US should be divided into 35 or so sections.
You can see where this would be counter productive to what you are looking for. I completely understand that you would like to have the location more easily available, this makes sense. Requiring the location in the topic description would accomplish this without having an absurdly huge amount of sub forums.
Understand that these numbers are rounded, and I just eyeballed the math.