Actually, I just went ahead and looked it up.

Your mean daily temperature in January is 36.9 degrees F. Also you mean annual temperature is 61.0 degrees F.

What this means is that your well water should come out of the ground at 61 degrees. Now if your average January atmospheric temps are around 37 I would assume that you get minimal ice coverage. This following comment may expose my ignorance, but I think it would be possible to create a thermal budget that could estimate what your pumping volume of 61 degree water would have to be to maintain an area of the pond at or above 40 degrees. I'll bet that it would be impossible to heat the entire pond, but maybe possible to create a warmer area of the pond that some of the shad could use as a refuge.

As a matter of fact, Nebraska has some power plant reservoirs that discharge warm water, 70+ F., that are used by some species of fish that get stressed by cold water. The gizzard shad will collect by the thousands near the discharge and some big predatory fish make a feast of stunned and disoriented baitfish.

I'm intrigued by the question, and I know to never say that something is impossible. There may even be some species of shad that would do better than others. I think that in some situations, it would be ideal for predators to have access to prey that spend a few weeks on the brink of freezing during the winter.

Holding a redear sunfish is like running with scissors.