Frozen pipes yes Bob , very bloody likely, when it is - 20f we open our
cabinets under the sink and some people even leave a drip. At -20f ive
seen mains freeze and pipes in enclosed cabinets freeze because of no
air circulation. Even at zero f. precautions must be taken. At - 20 he
will wake up to a 45 f house if it doesnt have great insulation, and
outside walls will be alot colder.