Wow, is this another form of movie merchandising?
Actually, it isn't such a weird idea. Not just hobbits, but Alice, too, fell down a rabbit hole. Pioneers to the Canadian prairies often lived their first winter in a hole carved out of a hill or dug into the earth. I would imagine the hobbit holes would have been a primary defense against the Fell Winter in the long ago days. Mount Doom's heat spread all kinds of ways!
