Throughout the weekend, Pepco said it hoped that restoration would be completed by 11 p.m. Sunday to most or all of those who had lost power during the storm.
Pepco also said crews will be held over in anticipation of more bad weather expected this week.
While restoration in the Pepco service area appeared incomplete, at least one neighboring power company, Baltimore Gas and Electric said its storm-response center was closed about 10 p.m. Saturday after having restored service to about 236,000 customers.
Although BG&E said storm restoration was complete, last night it listed 172 outages, presumably from other causes.
Dominion Virginia said electricity had been restored to affected customers by midnight Friday. Last night it listed about 1,500 outages in Northern Virginia, most in central Arlington. The causes were not immediately learned.
"This was the worst winter snowstorm we have witnessed on the BGE system in recent memory," company spokesman Robert L. Gould said. "It resulted in 65 percent more outages than the two blizzards in February 2010 combined."
Unlike last year's storms, which came to be known as Snowmageddon, Wednesday's storm delivered snow that was wet and heavy, weighing down power lines and trees.
"This was a massive storm that had extreme challenges associated with it, in terms of the destruction and what had to be cleaned up," Gould said. "The operating conditions were very severe."
In hard-hit Montgomery, Pepco customers said they piled on blankets, moved in with friends or relatives and headed to work Sunday in an effort to keep warm.
Michael Weiner of Gaithersburg said he spent nights at his father's house, while his wife and 4-year-old daughter visited relatives in New Jersey.
"Pepco's responsiveness to the situation has been abysmal," Weiner said. "You would think we were in Baghdad. But there are no insurgents bombing our power grid here.
"They talk about the five-year [reliability improvement] plan. Well, that doesn't help us now. We're in 2011; I don't want to hear about 2016."
Weiner's power was restored Sunday afternoon.
Pepco officials said they recognize a need to reduce the number and length of outages. A Washington Post investigation published last month found that Pepco's day-to-day reliability began declining five years ago and that Pepco ranks at or near the bottom in industry surveys of reliability.
The average Pepco customer experienced 70 percent more outages than customers of other big-city utilities that took part in one 2009 survey.