Is it cheaper to fly out of a U.S. airport?

If you’re booking a sunspot holiday this winter, you’ll notice that the flights are getting pricey. Back when the Canadian dollar was worth more, you could cut costs by driving over the border and flying out of a nearby U.S. airport. But is that still true, given the loonie’s recent decline? We crunched the numbers to find out.

Destination: Fort Lauderdale

Cost of departing from Toronto vs. departing from Buffalo, N.Y.

A week-long trip for a family of four leaving in early January would cost CDN$1,900 through a Canadian airline departing from Toronto’s Pearson Airport. From Buffalo the same vacation flights will cost $2,022, so no savings there. Still, if you’re willing to fly out at off-peak hours you can find U.S. deals. For instance, a family of four can fly for $810 on a non-stop flight from Spirit Airlines—saving about $1,100. The catch? Departure time is 2 a.m., with the return flight leaving at 10:15 pm.

Destination: Las Vegas

Cost of departing from Vancouver vs. departing from Seattle, Wash.

From Vancouver, a flight to Las Vegas would cost a family of four $1,700, and arrival and departure times work well with kids’ sleep schedules. But you won’t save money by departing from Seattle. Using Priceline.com or Kayak.com, this round-trip vacation costs $2,022—or $322 more. Still, if you opt for flights with late-night travel times, you can shave as much as $790 off the total price.

The verdict:

You can still save by departing from the U.S.—but only if you don’t mind red-eyes!