Worried about freezing pipes!

I dont think you need to worry about any pipes upstairs getting cold enough to freeze . Just open the closet doors on super cold nights and you should be fine.I have heated my home for 30 years with auxillary heat other than my oil eating furnace and never had a problem with freezing upstairs. Actually it sometimes gets too hot upstairs so I keep my door closed because I like it cooler. Just remember heat rises and plenty gets up there .
Just leave your oil boiler on at at a lower setting and if it gets cold in that zone it will just come on once in a while .
I never had a boiler and I have heard pros and cons about using antifreeze in them .Maybe just plumbers looking for extra work or trying to get out of it.
Cant see why antifreeze would bad myself and if power went out etc. you would have one less worry.

The antifreeze used in heating systems reduces the efficiency of the system by nearly 10 %. Yes it protects against freeze ups, but tiny leaks seem to become more numerous around/in valves, flow checks, fittings, etc. The stuff is REALLY
slippery in a heating system. As Freddie says, it REQUIRES a constant oversight to maintain the proper Ph or it goes acidic and eats up your system from the inside out, over time, if left unchecked. Kind of like the antifreeze in our vehicles. Leave it untested for years and see how the aluminum parts and gaskets like it. Tried to replace a thermostat 10 years later?
If you choose to use a 60 watt light bulb to help protect the area, better not mention it to anyone. I case you didn't know, building codes don't even allow an incandescent light bulb in a closet anymore. Gotta be a florescent now; fire hazard. Casually ask your local firemen about it. I like the separate thermostat idea or Greg's thermostatic heat tape idea. Is the loop piping pex or copper? Pex is forgiving, copper absolutely not.

PLEASE no heat tape or light bulbs in closets. we are busy enough with fires and accidents in the winter no need to create another. Leave the closet door open and monitor with indoor/outdoor thermometer. If it does get that cold and freezes a broken pipe would be better then a burned down ,water and smoked filled house. Please think safety of yourself and family FIRST,I don't want anybody to get hurt or property ruined from ideas to keep a pipe from freezing.
Chris H

UL approved heat tape is perfectly safe. I've never heard of a fire starting from its use.

A word of caution, however. Not all heat tapes are created equal and most present a potential fire hazard if they are not installed and used according to the instructions. The heat tape we use has a braided stainless steel exterior jacket housing a carbon-based inner core that self-regulates its heating. In other words, it only warms up as temperatures fall below 45°F and only where needed along its length. It can be overlapped and insulated without creating a fire hazard. Most cheap heat tapes can’t be overlapped or insulated because they overheat and pose a real risk for fire. Heat tapes must be plugged into a GFCI circuit.
The Consumer Product Safety Commission estimates about 2,000 fires, 10 deaths and 100 injuries involving heat tapes occur each year.

Found that which was one of many after I googled HOUSE FIRES + Heat Tape. I also know we have had a few houses and trailers over the years that the heat tape was determined as the cause of the fire
Chris H