They were doing it in the 1994 freeze (i think it was), it lasted until April, or
at least the line to one of our barns was,
we fed the barn using above ground hose
connected fed from the house, to a laundry
hose connected to the hose bib in the barn.
We never did it ourselves, as almost all of our undergroud plumbing is plastic.
I have herd of the steam pipe method too, connect a long piece of 1/8" or so
