It wasn't the party that they were expecting.
Donald Trump's surprise showing in the bitterly fought U.S. election came as a sharp surprise Tuesday to election watchers in Canada, including those gathered in the historic ballroom of a downtown Ottawa hotel.
The U.S. Embassy's viewing party at Ottawa's Chateau Laurier hotel started as a festive occasion, but the mood soon turned serious. The cocktail banter of embassy staffers, politicos and invited guests became decidedly muted through the night as big-screen TVs blared live coverage of Trump's gains in key swing states like Florida, Ohio and Michigan.
The sound was turned up on the television screens and stayed up for much of the evening as Hillary Clinton's expected victory — some said it would be a landslide — failed to materialize.
One woman covered her mouth and turned away from the screen, while another said, "Oh no!" one U.S.-born guest was overheard telling a friend they might have to reconsider moving back south of the border as planned.
"It appears we're going to have to still wait a little while to determine who is going to be the next president of the United States," U.S. ambassador Bruce Heyman told the few dozen embassy staffers, journalists and guests lingering shortly before midnight when the embassy had to pack up their party for the night.
"Regardless of who wins this race, the U.S.-Canada relationship will continue to thrive and be very strong," he said. "I know that we will continue to be the best friends, trading partners and allies as we face this new presidency."
A Trump presidency would surely have wide-ranging repercussions in Canada, said Laura Dawson, the head of the Canada Institute at Washington's Wilson Center, citing examples like climate policies, Syrian refugees and trade.
Trump has promised to gut environmental regulations at a time when Canada plans a variety of climate-change policies, including a carbon tax, she noted.
"Canada is going to be left with very, very, very expensive climate policies," Dawson said. "It will be a disincentive to investment and manufacturing."
Dawson was less convinced of major changes to trade policy. Other Canadians interviewed have also expressed doubt that his renegotiate-or-scrap threat about NAFTA would arrive at its most potent impact.
A president could rescind a trade deal. But the setting of tariffs belongs to Congress. Furthermore, remnants of the 1987 Canada-U.S. agreement could kick back in. Finally, the private sector, she said would revolt.
She said companies had remained silent during the campaign — but wouldn't accept such abrupt protectionism.
''All of those folks are going to be lined up saying, 'Are you kidding me? Do you know how much of our livelihood is dependent on open borders and trade between these three countries?''' Dawson said.
''There would be huge backlash.''
On refugees, Canada has thrown open its doors while Trump has appealed to his supporters by pledging to slam them shut — a sentiment that was thrown in sharp relief by a tweet that came from the federal government's official account just as the Republican candidate appeared to be picking up steam.
"In Canada, immigrants are encouraged to bring their cultural traditions with them and share them with their fellow citizens," the tweet read, prompting a number of users to suggest it was meant as an intentional jab.
Government officials did not immediately respond to media queries Tuesday.
Tuesday's narrow vote count was in many ways a fitting end to the angry and hard-fought presidential battle between Trump, the brash businessman-turned-improbable Republican nominee, and the would-be first female president in U.S. history.
Heyman predicted a smooth transition regardless of who wins.
"Having gone through the day, watching Americans coming out all across the country in record numbers and seeing the large number of votes that were in early, I'm very relaxed," Heyman said earlier in the evening, before results began coming in.
"One of the things we have to be most proud of is the smooth transitions in our government."
Retired Lt.-Gen. Charles Bouchard, who commanded the NATO force that backed rebels fighting Libyan President Moammar Gadhafi, called it a historic night that Canadians would be watching closely.
Bouchard knows the U.S. well having served Fort Hood, Texas military base on an exchange at NORAD in Colorado Springs and other U.S. postings during his Canadian military career.
"We wish them the best and we wish them a peaceful transition," he said.
Prime Minister Justin Trudeau's office said it would have no comment until a winner was declared. Finance Minister Bill Morneau and Environment Minister Catherine McKenna both came and went from the party without talking to reporters.
Fen Hampson, the head of the global security program at the Centre for International Governance Innovation in Waterloo, Ont., said Trump's success was reminiscent of the "Berlusconi effect," a reference to the former Italian leader Sylvio Berlusconi.
"Nobody said they supported him but he kept getting elected," said Hampson.
One Canadian official, who was not authorized to discuss the election publicly and so spoke on condition of anonymity, described a Clinton win as "same old, same old" when it comes to Canada's foreign-policy priorities.
Should Trump manage to pull out a victory, Canadians can take some measure of comfort in the fact Trump apparently has a lot of respect for Justin Trudeau and his international celebrity status, added the official, who has spoken to the Trump campaign about the prime minister.
"They think he's a showman.... They respect his success."
It helps matters that Trudeau has steadfastly refused to get drawn into the acrimony south of the border.
"You've noticed how careful our prime minister has been," the official said. "I think that was smart... You don't ever know."
Dawson said one of the biggest headlines for Canadians in the event of a Trump win — renegotiating or tearing up the North American Free Trade Agreement, or NAFTA — would in all likelihood never come to pass.
''All of those (companies) are going to be lined up saying, 'Are you kidding me? Do you know how much of our livelihood is dependent on open borders and trade between these three countries?' she said.
"If you were to impose a 30 per cent tariff on Mexico, the economic impact would be immediate, swift and would represent even more job losses for the United States."
Colin Robertson, a retired Canadian diplomat who served in the U.S. said a Clinton victory would have been better for Canada because it would ensure a level of continuity from Obama's two terms.
"We've already got a reset relationship starting in March, confirmed at the end of June when the president came up here."
— With files from Alexander Panetta in Washington, D.C.