Caught the end of the first episode the other night, and finally watched it from the start today. What a great cast. They absolutely nailed the atmosphere that was established in the movie. If you like the Coen brothers in general, you should really check it out.
I guess the long term plan is similar to that of True Detective or American Horror Story where it's kind of an anthology series. It's a singular story told over the course of the season, and if it were to be renewed there would be a new cast with a new story to tell.
Anyway, if you haven't done so, give it a watch.