Most shielded/sleeved PEX is typically, rated for extreme temperature ranges (high/low) and will hold its shape and integrity better in those situations. 

The following services are included: A physical walkthrough of the building to evaluate the potential presence of mold; Collection of tape lift samples of suspect mold and/or collection of air samples indoors and outdoors using slit-impactor Zefon cassettes, then submission of those samples for laboratory analysis; Temperature and humidity testing; Moisture testing using an infrared camera and pin-contact moisture meter; Collection of bulk asbestos survey samples of suspect materials which the consultant  feels will need to be disturbed to perform mold remediation work ;Testing of paint (per-1978 buildings only) and ceramic tile which the consultant feels will need to be disturbed to perform mold remediation work with an X-Ray Fluorescence machine; Photographs of the subject property and of situations or materials of note with regard to mold; Preparation of a formal report containing photographs, conclusions, recommendations, and laboratory report(s).

Therefore they need to convince me that it's worth my time to leave my warm cozy house and face sub-zero temperatures.

That means the the wild swings in temperature can make my problem even more common.

@Ryan Haase To follow-on to @Steve Babiak, there are several models of front-load, high-efficiency washing machines on the market which have built-in, in-line water heaters, which may be able to provide sufficient heat if your source water temperature is not too cold.  

Someone had abandoned a project halfway through and it sat, in unregulated temperatures for years.We pretty much redid the entire place.

Accurate pricing is fundamental regardless of the temperature of housing, especially in a declining market.

That said, if the roof isn't leaking and there are no substantial signs of damage, I can't imagine why he would need to replace it as long as it's still doing everything it was intended to do (keeping water out, helping regulate the temperature of the house, keeping pests out, protection from the elements, etc.).My questions is, has your dad filed an insurance claim, or just asking questions? 

My vehicle displays the ambient outdoor temperature. 

What is the average temperature in the United States right now?