Frillylilly, I agree on all points. But there is a store here that takes 'unwanted' fish. They offered mea a 2' koi a couple of years ago but it was winter and it never would have survived the transition. I didn't want a dead koi that big (or any size) in my pond all winter. It has happened, especially in the early years before we figured out the method for keeping them healthy all winter while they were dormant and the pond was almost iced over.
The big guy of ours, who can't fit into the caves very well any more just sticks his head in the cave entrance with most of his body outside. That way he can feel safe (?) and have the company (I guess) of the other fish in the long winter months.