Ricko, it would NOT be a good idea to import and release any snakes that are not native to your area. I'm pretty sure that you have Broad-Banded Water Snakes where you live, possibly Yellow-Bellies and maybe Northerns, but the others would not be native and introducing them wouldn't be good. Reptiles have a fairly well-developed "homing instinct" so a freshly-released snake is not likely to stick around where you want it to, and this is especially true during the breeding season, when males are going to wander some pretty far distances looking for females. Also, goldfish are VERY, VERY BAD for snakes to eat, since they contain an enzyme called "Thiaminaise" which inhibits the snake's body from being able to absorb vital nutrients from food, especially the Vitamin B complex, which will eventually result in severe neurological damage and death. And yes, snakes do hibernate just like turtles, and in many places, it's still a bit too cool for them. I'm in SC, and we're a lot further south than you, and I still have yet to see the first snake out here. I keep Nerodia, by the way, so I'm pretty familiar with these snakes.
S.A. McKenzie