Ahh...I had thought about that same thing. i'm building a deck around my 18' 52" pool (metal frame like yours) next year, and would prefer if I could some how "leave it up."
My main concern would be the freeze/thaw cycles. We get big chunks of ice on our trampoline, and man, as the edges melt, they are like razors. I would be concerned that as the under-water melts, the floating chunk might move a bit and damage the sides.
What I was considering is anchoring the base of the pool to the ground, as well as the top to the deck, draining it completely, then covering it with a winter cover to keep water and Crud out of the pool.
It's not a lot of water, but i guess if you're on city water, it might be expensive. We're on a well, so it's really cheap (pump electric only to get the water moved) to just dump and refill.
Do you think that would work?