Overnight, near-freezing temperatures gripped the U.S. northeast. At least two more victims were found in New Jersey, one dead of hypothermia, as the overall death toll from one of worst storms in US history climbed to at least 112.
Fuel supplies continued to rumble toward disaster zones and electricity was slowly returning to darkened neighbourhoods after a storm that hit the coast last Monday. New York Mayor Michael Bloomberg said it would be days before power is fully restored and fuel shortages end.
Bloomberg on Friday abruptly called off the city's marathon, which was set for Sunday, bowing to criticism that the event would divert resources from flood-ravaged areas. Hundreds of runners planned informal runs to deliver food and clothes to the borough of Staten Island and elsewhere.
More than 1,000 people, many who had planned to run the race, crowded onto two Staten Island Ferry boats early on Sunday, headed to the stricken borough with relief supplies including food and plastic bags to help residents store belongings from damaged or destroyed homes.
New York's Central Park was also crowded with runners near what would have been the marathon's finish line, scores of them shivering in the lingering overnight cold. A group called run4allcauses was collecting donations for Sandy victims.
Power restorations over the weekend relit the skyline in Lower Manhattan for the first time in nearly a week and allowed 80 per cent of the New York City subway service to resume. Some 2.5 million homes and business still lacked power across the Northeast on Saturday, down from 3.5 million on Friday.
Temperatures dipped to 39 Fahrenheit (4 degrees Celsius) early on Sunday morning in New York City, the lowest in days, with below-freezing temperatures expected on Monday. An early-season "Nor'easter" storm was expected to hit the battered New England coast this week with strong winds and heavy rain.
Bloomberg urged those without power and heat to head to shelters where they could keep warm and receive food.
President Barack Obama, neck-and-neck in opinion polls with Republican challenger Mitt Romney, ordered emergency response officials to cut through government "red tape" and work without delay to help affected areas return to normal.
Officials have expressed concern about getting voters displaced by Sandy to polling stations for Tuesday's election. Scores of voting centers were rendered useless by the record surge of seawater in New York and New Jersey.
New Jersey is allowing voters displaced by Sandy to vote by email. Some voters in New York could be casting their ballots in tents.
An NBC/Wall Street Journal poll released on Sunday found that 68 per cent of those surveyed approved of how Obama handled Sandy and just 15 per cent disapproved.
The post-storm chaos in the region has overshadowed the final days of campaigning.
"I'm not thinking about the election too much right now," said Frank Carrol, 59, a retired New York City transit worker who lives in Staten Island. He planned to vote, but did not know if his local polling station would even be open. "We'll stop by and see what happens," Carrol said.
New Jersey Governor Chris Christie ordered county clerks to open on Saturday and Sunday to accommodate early voters and ensure a "full, fair and transparent open voting process."
New Jersey authorities also took the uncommon step of declaring that any voter displaced from their home by Sandy would be designated an overseas voter, which allows them to submit an absentee vote by fax or email.
The two new deaths in New Jersey - where the storm came shore last Monday night - included a 71-year-old man who suffered from hypothermia and another man, 55, who died from smoke inhalation in a house fire, police said on Sunday, raising that state's death toll to 24.
On Saturday, Bloomberg put New York City deaths at 41.
Sandy killed 69 people in the Caribbean before turning north and hammering the US Eastern Seaboard on Monday with 80 mile-per-hour (130-kph) winds and a record surge of seawater that swallowed oceanside communities in New Jersey and New York, and flooded streets and subway tunnels in New York City.
As the biggest U.S. city slowly returns to normal, Bloomberg said the "vast majority" of New York's 1,750 public schools would reopen on Monday.
New York City's overstretched police got a break with the cancellation of Sunday's marathon, a popular annual race expected to draw more than 40,000 runners to the city.
Lara Duerrschmid, 27, was among the marathon runners boarding a ferry to help residents of Staten Island. "I know it's going to be tough to see (the damage), but I just wanted to do something good," she said.
Tight gasoline supplies have tested the patience of drivers - fistfights have broken out in mile-long (1.6 km) lines of cars - but a reopened New York Harbor meant fuel was reaching terminals.
Bloomberg said the fuel shortages would be easing soon, and the US Department of Energy confirmed on Saturday that most filling stations in the metropolitan area had fuel.
Some 731,490 customers in New York state were still without power, the governor's office said on Sunday. In Manhattan, electricity had been restored to most neighbourhoods.