Keeping water in Trail'd spare tire water tank year round

[broncot]

Picked up several of these second hand ($80 each) and plan to use them for trips and also emergency water bug out style. Other than not filling the tank fully, what precautions should I take to avoid damaging the tank during winter? The company doesn't offer much guidance.
I plan to empty the tank periodically to keep the water fresh and usable.

 

[NatersXJ6]

My years of cold-climate living say don’t bother filling it in the winter. Unless you keep it inside the heated space of the vehicle, it is unlikely to be liquid when you need it, and you probably won’t have a way to heat it safely.

If you really want it, maybe just fill to about 3/4 or slightly less to allow expansion room, but there is probably still risk, it could rupture.