Before you freeze the commercial jugs of unopened water do an experiment. Get an identical empty jug from somewhere, fill and freeze it. See if the sides bust out or the top comes off. Make sure you place the jug in a baking pan just in case of failure.

Reason: I had friend that froze his milk and never had a problem. We also thermal-massed our chest freezer with water in the same manner incident-free. Give it a whirl.

Two cents....