One way of avoiding expensive damage, is putting antifreeze in the hydronic system piping.
This will protect the baseboard, piping, boiler, and or radiators from freezing, even if the power is off or something wrong with the system. A feeder for antifreeze can be added, that runs off of battery power, which is continuously charged.
If you don't have to worry about the heating system freezing, then the domestic water lines can be drained if leaving the house for an extended time, and the main water source protected by either heaters or heat tape.
Insulation alone is not enough, as it can only hold in heat, not produce it, and whatever heat is contained by it, will eventually pass through and be lost.
Moving water can not freeze, so another method is to set up a hydronic system to run the circulator pump continuously and only cycle the burner with thermostat.
This can not be done with zone valves, only with a single zone or multiple zones, each with thier own circulator.
As long as the water moves, it won't freeze.
However it's much safer to add antifreeze because if power is lost for any reason, it will freeze.
