Not many people fly on Christmas Day, which is why airlines need to fill up seats with super low fares. Air Canada has a sale right now with some amazing one-way fares, such as Los Angeles to Montreal for $99 and Las Vegas to Montreal for the same price. Montreal to Ft. Lauderdale is just $79 each way.
We found that these fares are only available on Air Canada's Web site, not on Kayak, Orbitz, etc., as shown by the screen shots below. This sale ends Dec 5.
LA to Montreal leaving Xmas Day, returning Dec 31 on Travelocity, all Air Canada flights $427 RT with taxes:
LA to Montreal, same flights and travel days, on Aircanada.com $348 RT with taxes: