Thousands of Canadians who have been without power since last week's fierce winter storms spent Boxing day in the cold and dark while strong winds and high tides on the West Coast prompted a flood warning.

The City of Vancouver issued a flood warning Monday evening, saying "exceptionally high tide and high winds" are forecasted for Tuesday due to storm surge, with "moderate to elevated" risk in some low-lying coastal areas.

"Water levels are forecasted to be at their highest at 9:00 am … (on) December 27, when a king tide combined with a significant storm surge of ocean water from the incoming storm is anticipated to raise the tide to a historic high," read a statement.

On the other side of the country, utility crews in Ontario, Quebec and New Brunswick continued working to restore electricity to thousands of customers who have been in the dark for days.

Some train service will soon be back to normal, however, with Via Rail announcing plans to resume trains on its Toronto-Ottawa and Toronto-Montreal routes Tuesday, days after a CN train derailment forced the cancellation of those trains scheduled for Christmas and Boxing Day.

CN confirmed in a statement that the tracks where its train derailed on Christmas Eve will be reopened Tuesday and said Via Rail plans to run all trains on the route, but on a modified schedule available on its website.

As of Monday evening, power was still out for over 42,000 Hydro-Québec customers and over 11,000 Hydro One customers.

New Brunswick Power had restored power by Monday evening to a majority of customers who were impacted by the storm, which it said was one of the largest provincewide outage events of the last 25 years. The utility said just under 300 customers were still in the dark as of Monday evening.

NB Power said earlier Monday it was confident there would be some customers still without power on Tuesday.

Hydro One in Ontario said it had restored power to more than 430,000 customers since the extreme weather began, but persisting road closures were impacting its crews' ability to access restricted areas.

"Crews are out in full force and have gained access to Walkerton, Picton, Prince Edward County, Napanee and Trenton," it said in a statement issued Monday evening.

"Efforts to reach customers in Bracebridge and Huntsville continue. Conditions in Bracebridge and Parry Sound may worsen with up to 50 cm of additional snow expected."

Hydro-Québec CEO Sophie Brochu said earlier Monday it was hard to provide a precise estimate for when power would be restored to the customers still without due to the complexity of the remaining jobs.

Brochu said more snow and high winds had complicated access to the sites, many of which were set back from roads and could only be reached by crews on snowshoes or snowmobiles. About half the remaining outages affected five customers or less, which means crews were "working very hard to restore a few people," she said.

“We might be working three, four, five hours for a team of two to restore five people,” she told reporters in a virtual press briefing Monday morning. “It’s worth it, don’t get me wrong, but it means that instead of working five, six, seven hours and restoring 1,000 people, every (segment) is really slow.”

She acknowledged customer frustration with the inaccurate estimated timelines on Hydro-Québec’s website, saying crews sometimes discover more problems once they arrive. While the “vast majority” of outages will be resolved by Wednesday, she couldn’t promise that nobody would be in the dark by New Year’s Eve.

“Nobody will be forgotten,” she said. “We will have no surrender and no peace until everybody is connected back.”

Southern Ontario's Niagara Region was in its third day under a state of emergency on Monday due to the storm, and some services like garbage and recycling collection were cancelled for Boxing Day.

Environment Canada issued a snow squall warning for the region and warned of reduced visibility due to snowfall that could last until Tuesday afternoon in some areas.

Other parts of southern Ontario like Barrie, Parry Sound and Grey-Bruce remained under similar warnings Monday evening.

The weather agency also issued wind, freezing rain and snowfall warnings for parts of Alberta, Manitoba and British Columbia, as well as for extreme cold in some parts of the Northwest Territories and Yukon.

Meanwhile, it said temperatures will rise well above the freezing mark throughout much of southern Quebec and Atlantic Canada beginning Wednesday.

Temperatures in Montreal are expected to rise to between 0 C and 9 C during the day and up to 7 C at night. Similar conditions are expected further east, with temperatures approaching 10 C in Fredericton and Saint John, N.B. and Charlottetown, while Halifax could hit 11 C on Saturday.

The warmer weather is expected to last at least four days, until New Year’s Eve.

Environment Canada warned of ice buildup from ongoing freezing rain in the southern area spanning Whistler and the Fraser Valley to the Okanagan Valley, as well as a special weather statement for much of the Interior, also for possible freezing rain.

Police in British Columbia have said they believe icy conditions played a role in a bus rollover on a highway in the province's interior Saturday night that killed four people.

This report by The Canadian Press was first published Dec. 26, 2022.