keep it! today i found a dead gardener snake, it got him on the tail and died since it was so cold.
its a coincodence that you found it. If it haddent been u or another house, it'll be dead anyway. I think it was planing on finding a small rodent den or something to hibernate.
I say keep it till spring, that little thing is cold and hungry, u dont want it to, do you!? u can ship him to me, i'll take care of it till then