The outside pipes are pretty deep... we're on our township water system and about 10 years ago had to replace the pipe from the main at the road to our house; the contractor put it down in a ditch that was over 6' deep, so we haven't had any problems with it. There are always LOTS of frozen and broken water pipes up here, though -- often the water depts will have the customers keep the water running (they always say "in a stream the size of a pencil") so that it won't freeze. The snowbirds that leave their house to head south in the winter generally have all the water shut off and the pipes drained, antifreeze in the toilets and traps, etc etc.
Always seems pretty miraculous to me that any kinds of plants can survive, to say nothing of the songbirds and the animals out in the woods
