Many public schools, including those in Worcester - the state's second largest city - were closed with local emergency declarations still in effect in dozens of communities.
James Mannion, spokesman for the Massachusetts Emergency Management Agency, said conditions in some of those areas made it too dangerous to hold school.
"Roads aren't safe to drive on and there might be power lines down. It isn't safe for kids to get around," Mannion said early Monday.
Peter Judge of the Massachusetts Emergency Management Agency said that access to downed power lines and poles remains the biggest obstacle for workers, reports CBS Station WBZ-TV in Boston. While the major roads are cleared, many secondary roads in rural areas remain blocked by fallen trees and tree limbs.
Power companies in New Hampshire, Vermont, Massachusetts, Maine, Connecticut and upstate New York reported Sunday and early Monday a total of 423,200 customers were still without power. Crews from Canada and as far away as Virginia and Michigan were assisting in restoring power lines.
While some took refuge in shelters, others have been checking in to hotels and motels, including the Howard Johnson Inn in Hadley.
"Half of our rooms have been taken by families coming with their kids and even some dogs," Rick Kim, guest services agent for the hotel, told The Republican newspaper of Springfield.
President George W. Bush declared a state of emergency in New Hampshire and in nine of Massachusetts' 14 counties, directing the Federal Emergency Management Agency to provide relief assistance.
New Hampshire, Massachusetts, New York and Maine declared either limited or full states of emergency Friday. Crews across the region reported the ice had destroyed utility poles, wires and other equipment, but said the extent of damage was unclear because some roads still were impassable.
As of 4 a.m., Mannion said there were approximately 118,500 electric customers in Massachusetts without power, down from a peak of 350,000 in the immediate aftermath of the storm on Friday.
New Hampshire, the hardest-hit state, was down to about 168,000 customers without power Monday morning, compared to a peak of 430,000 on Friday, utilities reported. There was also 94,400 without power in New York; 35,000 in Maine; 6,195 in Vermont and 1,104 in Connecticut.
Access to downed power lines and poles remains the biggest obstacle for workers. While the major roads are cleared, many secondary roads in rural areas remain blocked by fallen trees and tree limbs.
The potential for high winds and rain over the next 24 to 36 hours is likely to affect efforts to restore power and may also create additional outages in Massachusetts, National Grid said in a statement.
Mannion said an estimated 2,200 residents without heat or electricity spent the night at 62 emergency shelters around Massachusetts.
In Kennebunk, Maine, Holmes Tree Farm closed on Friday but reopened Saturday. Diane Holmes said people were getting antsy in their homes and needed fresh air. They also needed to return to their holiday traditions. By Sunday, several hundred trees had been sold.
Holmes said the ice-laden balsam firs sparkled in the sunlight, but the ice made them heavy. "I'm telling people, bring a lot of muscle," she said.
In Vermont, Green Mountain Power President Mary Powell was touring affected areas and helping distribute lunches to the line crews. She said the damage caused by the storm rivaled or even exceeded the 1998 ice storm that hit northern Vermont.
"Whenever you get this kind of ice accumulation, there's just nothing from a utility perspective you can do to protect your customers from devastating damage," Powell said.
Emergency management officials reported four storm-related deaths. A Danville man died of carbon monoxide poisoning from the generator he was using after his power went out Thursday night. Carbon monoxide from a gasoline-powered generator killed a couple in their 60s at Glenville, N.Y., police said Saturday.
The body of a Marlborough, Mass., public works supervisor was recovered from a reservoir Saturday, a day after he went missing while checking on tree limbs downed by the ice.