Not sure what you are heating the radiators with. Is there a separate boiler that heats the radiators or does the gas water heater heat them also?
In either case, the water could be shut off and the traps and toilet bowls filled with trailer antifreeze. The water heater would be shut off and drained because disease can breed in water held inside for a long time.
If a separate boiler heats the radiators, then the gas should be left on to keep the system from possible freezing. Set the thermostat to 55F.
http://www.heatpro.info heat/cool right-sizing
The Senate and House can not find a suitable health plan for the nation; they should open their own exclusive health plan booklet and start reading.