If the Hobbit edit ever happened, it would be a lean 2-2.5 hour affair somewhat in the vein of The Little Hobbit
My notes at the time can be found here: https://forums.fanedit.org/showthread.php?tid=15702
So not really going for a purist book cut or anything, it would be an attempt at using the best material available from the films regardless of whether or not it appeared in the book. Tauriel for example would retain a substantial role despite being wholly generated for the films.