A time-tested mouse trap is a bucket partially filled with water.
Now we have closed up the camp for the season. Kathy put dryer sheets in some spots as a minor deterrent. And yes, the water system is disconnected until next May. The pump and the expansion tank are in our warm enough basement. Any water remaining in the pump or tank could expand and cause pump or tank to fail. The under the camp water supply lines should be okay. Recreational grade anti-freeze goes into the traps and the flush. We need to remember and empty any milk jugs that we use to carry drinking water from the spring. The master circuit breaker is off and the refrigerator doors are open.
So, mice are now the winter tenants.