certain urethanes gets very brittle in cold weather, it all depends on the materials brittle to ductile temp. Potentially a urethane material could be much weaker than a fiberglass material in the cold weather months, especially up here in MI. You would want the Ductile to Brittle temp to be well below -10 F to have a saftey margin. Depending on the D to B temp I would be interested.
