@ifixcoinops There are variable refrigerant flow systems that can do something like this, almost certainly including water heating, but I suspect finding people capable of installing them is extremely difficult in the US. The installer will almost certainly need to travel to you. I suspect most such systems also involve geothermal.

With geothermal it might make sense to connect the refrigerator, since the water will likely be below the ambient temperature. But refrigerators tend to be optimized for room temperature anyway, so I think it would only be a tiny difference from dealing with the air conditioned room temperature.

I close the basement central air vents in the summer to keep the water heater from overcooling the space. I'll open them enough in winter to keep the space warm enough to prevent the resistance coil from operating, but no more.

The water heater seems sufficient to keep the basement dehumidified as well, which is nice. The dehumidifier barely ever kicks on.