* Death toll rises to 110
* Fuel flowing again after New York Harbor reopened
* Manhattan skyline relit, subways mostly restored
* Disaster victims, first responders under strain
By Joseph Ax and Jonathan Spicer
NEW YORK, Nov 3 (Reuters) - Fuel supplies headed toward disaster zones in the U.S. Northeast on Saturday and a million customers regained electricity ahead of a coming cold snap that threatened to add to the misery of coastal communities devastated by superstorm Sandy.
The power restorations relit the skyline in lower Manhattan for the first time in nearly a week and allowed 80 percent of the New York City subway service to resume, but 2.5 million homes and businesses still lacked power, down from 3.5 million on Friday.
The power outages combined with a heating oil shortage meant some homes could go cold as wintry weather sets in. Forecasters saw temperatures dipping into the upper 30s Fahrenheit (around 3 degrees Celsius) on Saturday night with similar low temperatures next week.
"There's no heating oil around," said Vincent Savino, the president of Statewide Oil and Heating, which usually supplies some 2,000 buildings across New York City. "I don't know how much fuel we have left: maybe a day or two."
The long, arduous recovery was taxing disaster victims and first responders strained by a week of emergency services.
The post-storm chaos also threatened to jumble Tuesday's election with President Barack Obama and Republican challenger Mitt Romney locked in a tight race.
The storm's death toll rose to at least 110 with nine more deaths reported in New Jersey on Saturday, raising the total in that state to 22. New York revised its total down by one to 40.
Sandy killed 69 in the Caribbean before turning north and hammering the U.S. northeast coast 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.
"It's just breathtaking," said New Jersey Governor Chris Christie, who ordered rationing that allows only half of all cars to buy gasoline each day. "I was there (at the Jersey Shore) yesterday and I will tell you, it looked like we had been bombed. There are homes in Bay Head on the beach that had been driven by the storm surge into the houses across the street."
Tight gasoline supplies have tested the patience of drivers - fist fights have broken out in mile-long lines of cars - but fuel was making its way to terminals after the U.S. Coast Guard reopened New York Harbor to tanker traffic on Friday.
Alleviating one of the country's worst fuel chain disruptions since the energy shortage in the 1970s, some 8 million gallons of gasoline and other petroleum products have been delivered since Friday and another 28 million gallons was to be delivered this weekend, New York Governor Andrew Cuomo told a news conference.
Cuomo also announced the Defense Department would set up five mobile gas stations in the metropolitan area, providing people with up to 10 gallons of free gas.
At least 1,000 drivers queued up at the Freeport Armory in Long Island, only to be told the gasoline would not arrive for at least eight hours more, one driver said.
"There's just so many people getting very frustrated. People don't know what to do," said Lauren Popkoff, 49, a history teacher who had been in line for four hours.
New York City gave its overstretched police a break by abruptly reversing course on Friday and canceling Sunday's marathon, a beloved annual race that had become a lightning rod for critics concerned it was a diversion of resources.
In one hard-hit Queens neighborhood, a garage full of debris stood open with a sign next to it reading: "LOOTERS WILL BE CRUCIFIED - GOD HELP YOU."
"Hurricanes can be the stress equivalent of cancer," said David Yusko, assistant clinical director at the Center for the Treatment and Study of Anxiety at the University of Pennsylvania.
Obama won early praise for the federal response to Sandy but faced continual television and newspaper images of upset storm victims.
The storm damaged or destroyed thousands of homes and displaced voters, forcing election officials to improvise at affected polling stations.
Christie ordered county clerks in New Jersey to open on Saturday and Sunday to accommodate early voters.
"There's no reason why anybody shouldn't vote. We're going to have a full, fair and transparent open voting process," Christie said.
Before heading to the Midwest on Saturday for a final weekend of campaigning, Obama visited Federal Emergency Management Agency headquarters in Washington for a briefing, and told officials to cut through government "red tape" to help storm-ravaged areas.
"There's nothing more important than getting this right," the president said at the beginning of a briefing with officials from FEMA, the Department of Homeland Security, and state and local governments.
Moving to ease fuel shortages, the Obama administration directed the purchase of up to 12 million gallons (45 million liters) of unleaded fuel and 10 million gallons (38 million liters) of diesel, to be trucked to New York and New Jersey for distribution.
The government announced it would tap strategic reserves for diesel for emergency responders and waived rules that barred foreign-flagged ships from taking gasoline, diesel and other products from the Gulf of Mexico to Northeast ports.
Power utility Consolidated Edison, battling what it called the worst natural disaster in the company's 180-year history, restored electricity to Manhattan neighborhoods such as Wall Street, Chinatown and Greenwich Village in the pre-dawn hours, leaving 11,000 customers in Manhattan without service.
Con Ed said it had restored power to 70 percent of the 916,000 customers in the New York City area who were cut off.