ORLANDO — The NFL has a clear vision of what its ideal regular season looks like. And like a pound-and-ground offense that keeps churning downfield, one 5-yard run after another, the end zone is now within reach. The league’s nirvana is an 18-game regular season and one international game for each of its 32 franchises. It will be a few years before that happens, and the players and their union will ultimately have a say in all this, but the seeds haven’t just been planted; they are taking root.