An online travel company in Canada has a similar promo,
"if it snows more than 5"s on New Years day your travel is free if you book between between June 17 and October 19 for departures between November 1, and April 30"
Last winter, they paid out in Quebec, Toronto missed by a quarter inch, and down east they got 9" but over Jan 1 and 2... Even out west they had a pretty good snow, but shy....
It was all over the news when the forecasts came in for New years day..., if Calgary, Toronto, and Halifax all hit the mark, the company or its insurance policy would have taken a huge hit...
Andrew