Heating with wood only, protecting pipes

[SailinAway]

I've never heated only with wood. I'm wondering what I need to be aware of to avoid freezing pipes.

I maintain the temperature on the main floor at around 64 to 66 (personal preference).

Two-story cape. Upstairs there are radiators in two bedrooms and the bathroom. I've always kept the radiators closed in the bedrooms and open in the bathroom. The bedroom radiators are on exterior walls. I "assume" they're empty, thus can't freeze(?).

I'm not yet comfortable leaving the woodstove burning all night. I will reread last year's thread on maintaining a fire. It contained a lot of good information that we don't need to repeat here.

Would the simplest solution be to set the furnace (remember, that's the thing that some call a boiler) to 45 degrees so that it never comes on during the day and occasionally comes on at night? In extremely cold weather I also know to leave the kitchen and bathroom sink cabinet doors open, especially with pipes near exterior walls.

In past years the temperature in the cellar has been about 45. Is that a concern if the furnace isn't running and not contributing heat to the cellar? Or will the fact that the cellar is underground keep the temperature above freezing?

Anything else I should be thinking about?