At least five deaths were blamed on the storm.
The Massachusetts Bay Transportation Authority, or MBTA, warned riders that the storm could affect Monday morning commute. And with the chilly temperatures and piles of snow, Halloween plans were touch and go for many cities.
Worchester, Massachussets, asked residents to postpone celebrations until Thursday when temperatures are expected to climb to 60 degrees.
"Safety doesn't take a holiday. Halloween tomorrow night will put families and our youth in harm's way as they negotiate piles of snow and downed limbs," the city said Sunday night.
Some of the heaviest snow fell in Massachusetts, Connecticut, New Jersey and New York, but snowfall amounts of at least a foot were recorded from West Virginia to Maine. The Berkshire County community of Peru, Massachusetts, received 32 inches of snow during the storm.
"I never have seen this and I've lived here all my life, and that's more than 90 years," 92-year-old Genevieve Murphy of Westfield, Massachusetts, said in an interview with CNN affiliate WWLP-TV.
Aaron Kershaw in Mahopac, New York, about 50 miles north of Manhattan, told CNN he was using a 4,000-watt generator to provide power for his family of five.
The wet, heavy snow brought down a number of trees, while coating the area in a think blanket of white.
"Thank God no homes, cars, people etc. were harmed," he said. "But Mother Nature left us beautiful scenery."
With no electricity and no heat, Jessica Taylor took her six children and spent the night in a shelter in the Hartford, Connecticut-area.
"We've been eating meals here," she told CNN affiliate WTIC-TV. "They've been serving us, taking good care of us."
Early Monday morning, the state's largest utility -- Connecticut Light and Power -- reported nearly 757,000 customers were still without electricity.
"It's all hands on deck," said Mitch Gross, a spokesman for the utility. "We have a lot of work to do."
Power crews from across the country are converging on the state to help restore power," according to Gross, who said every town Connecticut Light and Power service was adversely affected in some way by the storm.
Elsewhere, about 236,000 customers were without power early Monday in Pennsylvania; 539,000 in Massachusetts' 383,000 in New Jersey; 280,000 in New York and 228,000 in New Hampshire, according to figures from power companies in those states. Thousands also lost power in Maryland, Virginia and West Virginia.
Kimberly Lindner, of Chappaqua, New York, said the family whiled away the hours by building a "jack now-lantern."
"It's October and there are 12 inches of snow on the ground," she said in a submission to CNN's iReport. "But the kids think it's great. They've been playing outside all day and really don't care that there is no power. Why not make the best of things and have some family time in the snow? A snowman without a head, a jack o-lantern without a body... enough said."
For others, however, the unexpected storm brought unexpected misery.
Forty-eight passengers were stuck in an Amtrak train for nearly 13 hours when a rock slide blocked the tracks late Saturday night, the transit service said. A bus was later sent to pick up the passengers.
"The noise of the branches when they were falling and hitting the windows, they made us all sit in the aisle seats," Ann Amphlett, a passenger, told CNN affiliate WHDH.
Airline passengers left stranded by the storm spent a restless weekend night on cots or airport floors.