A few helium miners in the middle of nowhere

So, I live in a pretty rural area. The town and surrounding farmers probably consists of 15,000 people. I read somewhere that a challenge only occurs after 300 blocks (I don’t know if that’s based on a single hotspot or the whole network). If I create a network of hotspots, so they can talk to each other, but they’re out in the middle of nowhere, where I’m not sure a lot of data will actually flow, will I actually make money?
I’ve looked on the helium hotspot map at similar scenarios, where there are 2 or 3 close together, but far away from other large groups (so I assume they are rural towns like mine) and their making $10 a month. Are they a good comparison for me, or have they just not optimized their miners?
Thanks in advance for the feedback!