Utility crews from Maine to Michigan and into Canada worked Wednesday to restore power to hundreds of thousands of homes and businesses left in the dark by last weekend’s ice storm, and people slowly trickled out of shelters to spend Christmas Day at their finally warm homes.

The frigid temperatures that cloaked a region from the Great Lakes to New England meant that ice remained on power lines and tree limbs. Officials worried that wind gusts of more than 20 mph could bring down more branches and that 2 to 6 inches of snow in places on Thursday would hamper line crews trying to get to remote spots.

“We’ve had two beautiful, sunny days in Maine, and the ice isn’t going anyplace,” said Lynette Miller, spokeswoman for the Maine Emergency Management Agency. “They’re very concerned about more weight coming down on trees that are already compromised by ice.”

The ice storm last weekend was one of the worst to hit during a Christmas week, and repair crews were working around the clock to restore service. States that weren’t hit were sending crews to help.

Authorities blamed the storm for 17 deaths in the United States and 10 in Canada, many attributed to carbon monoxide poisoning from emergency generators powering homes. In Michigan, police said a woman died Tuesday when she drove through an intersection where the traffic light was out of service because of the ice storm and collided with a pickup truck.

Tens of thousands of homes were still without power on Wednesday in Michigan, down from more than 500,000 at the storm’s peak; in Maine, down from more than 100,000; and in Toronto, down from 300,000.

Ashley Walter was forced to spend Christmas at a shelter in a school in Litchfield with her husband, Jacob, and their month-old daughter, Leah.

The family lost power Saturday, got it back and then lost it again Sunday. Ashley Walter, 27, and Leah have stayed warm at the shelter while Jacob makes frequent trips home to check on the cats and water pipes.

“It’s definitely kind of strange, but we’re hanging in there,” she said .

Trudy Lamoreau was supervising the emergency shelter where about 25 people stayed Tuesday night.

“People are doing quite well considering the circumstances,” she said.

Volunteers tried to make the shelter homey, including cooking a ham dinner with potatoes, vegetables, bread and pie for Christmas.

In Michigan, about 156,000 people were still without power Wednesday afternoon, down from more than 500,000 at the storm’s peak. Snow is falling across most of the state, and temperatures were in the teens and 20s.

So far, authorities blame the storm for 25 deaths; 15 in the United States and 10 in Canada, including five people who apparently died of carbon monoxide poisoning. In Michigan, police said a 73-year-old woman died Christmas Eve when she ran a stop light that was out of service because of the ice storm.

In Canada, about 160,000 customers were without power Wednesday. There were 72,000 customers without power in Toronto, down from 300,000 at the height of the outages, and Mayor Rob Ford said some might not have power restored until the weekend.

Back at the shelter in Maine, volunteers have tried to make it homey. For Christmas Day, they cooked a ham dinner with potatoes, vegetables and bread — and pie for dessert.

“They have been amazing,” Walter said, adding that the volunteers set up a separate room for her and Leah so they wouldn’t disturb others when the infant woke during the night. “They just try to make everything better for us.”