Make it accessible to more people, while also keeping the niche appeal.
I think Community has reached equilibrium. There is no crossover appeal; the viewers they have are going to be a combination of the viewers they've always had and whatever new viewers they obtained through syndication. Unfortunately no matter how hard they try, I doubt anyone is going to say "Hey, what's this Community show that's been on for four years? Maybe I'll tune in this Thursday and check it out!"