My state (CO) also has 6 man football and hours distance between the schools. Do the rural schools that combine to form a team hold practice at their respective schools and form their teams at competitions?
Only HS students are allowed in sports, but pretty liberal otherwise. Homeschooled can participate at school of choice (not a fan). If your school doesn't sponsor a sport, play wherever you want. For that matter, you can generally attend any school you want.