Why don’t you ask the insurance company? If I were you I would be more worried with the rental company providing a car without snow tires..
In addition, road closures can occur but, if it is just snow, are often quickly resolved. So I would not worry too much. It is also difficult to prove to the Insurance that road has been closed. For flights etc. this is simply as you will always have an email from the airline.
Credit:stackoverflow.com‘