You do realize that as you pump hot air out of the house, towards your pipes, that the air has to be replaced by other air? Most likely this is cold outside air. So your heating bill would go up, to heat that cold outside replacement air.
I know there exist electrical heaters for waterpipes. Have never seen or used them myself.
Also, adding a drop of glycerine to potable water drastically reduces the temperature at which it freezes. AFAIK glycerine isn't poisonous.
Just some random thoughts I had.