TRUST ME on this...
CO is pretty easy. Go try Delta. "okay so I can't leave Jan 3rd, fine when is the next available seat. Ah... March 17th. Okay and the first day I can return? Ahhhh Dec 19th... um no I would NOT like to book it."
Delta is nuts. I view the miles as pretty numbers to look at. Kind of like ART. It costs alot, and just is there... can't do much with it.