Freezing Winters in the Midwest cities and Plumbing Concerns

[Leo B.]

In Midwest cities such as Indianapolis, Detroit, Milwaukee where there can be some really cold winters, is there a concern about the old plumbing system in the home?  I've heard of old pipes bursting and causing costly repairs as a result.  How do you mitigate against these risks if there are no leaks in the meantime?  Do you re-plumb the entire house?  Is there additional supplemental insurance you can purchase as part of the homeowner's insurance policy?

I've heard of some rehabbers replacing the entire plumbing system with PEX plumbing.  What is the average cost to re-plumb an entire house in those areas?