Should we turn off the water?

When we leave our Adirondack cottage in cold weather, the water pump is turned off and the pressure in the pipes is relieved. The thermostat for the LP hot air furnace is set at 45 deg.F. We have two inside temperature sensors (and one outside) that wirelessly connect to an AcuRite AcuLink Internet bridge that uses our cable Internet connection to transmit the humidity and temp readings to a central server that we can access at any time from our PC's or an app on our phones. The AcuRite system is set to notify us if a sensor temp drops below a preset value, the sensor batteries are getting weak, or there's a loss of signal. Our two daughters lives just a short distance away and regularly check on the place, and in the event of a low temp alert, can be there in quickly to handle any problems.