If you have water shut off and pipes drained prior to the BG FREEZE. My plumber is saying rather than turning water on for a day or two and then having it inspected. Have a plumber come out, he will turn water on at meter, and put a meter on the line to test for leaks. That way if you do have a leak and you are not at the house you will not have major damages to explain. to you seller. AND you sure do not want to have to tell the seller you made a mistake and how are you going to pay for your mistake?