Just don't move to those regions. The United States is the third or fourth largest country in the world by land mass. There are properties you can buy which are inside the range of only one terrestrial ISP, or none at all. Don't do it if access to more than one terrestrial ISP is important to you.
Also, I don't know if you're referring specifically to the UK. I happen to have some experience with the ISP situation in Canada, and I can tell you that there are places smack-dab in the middle of the largest city in the country where you only have access to one ISP. There are really only about four, maybe five, functioning terrestrial ISPs in Canada, and in a given city, usually only two operate. I have no idea how sparse it gets out in the sticks, cottage country at least gets LTE. Generally the only terrestrial ISP competition in Canada is between monopolies on roughly either side of the continental divide in telephone DSLs (Bell or Telus, depending on region) and modems on the cable TV infrastructure (Rogers or Shaw, depending on region), a fifth is coming up just in Toronto (Beanfield), time will tell if they can manage to expand the fiber infrastructure enough to grow their business.
The UK, along with all other commonwealth countries, has no equivalent rules to repeal or support.