The premise of the movie from Worth Reviews:
Based on a true story of a hermit who lived for forty years in the Tennessee woods. Felix Bush (Duvall) decides it is time to plan his funeral. But his funeral will not be any old macabre occasion. Organized by a local undertaker played by Bill Murray and his sidekick played by Lucas Black, the funeral will be more party than memorial and an event to which anyone and everyone will be invited and at which Bush will reveal a long kept secret.