Refugees from "Blackout City," the portion of Manhattan that has been without power since late Monday, have been flowing north into parts of the city where life has been fairly normal this week - at least on the surface.

Inside the area's expensive homes, it's a different story.

AJ Feld, 24, found the sleek two-bedroom apartment he owns on 78th Street and West End Avenue overflowing on Monday night.

Three young women - only one of whom Feld knew well from his days at Duke University - were sleeping in his bed. Three more of his friends were on the wraparound sectional couch in his living room and he was on the floor of his second bedroom, having been elbowed out of bed by the seventh refugee-friend.

"We've kind of just been inviting whoever," said Feld, who works on business development for a health care startup. "I just haven't had that many people up here before."

Five of the people who stayed with him that first night when the power went out had left to stay with other friends, but two guests still remained by Thursday.

Electricity for the bottom half of Manhattan was cut off late on Monday after damage from the massive storm triggered an explosion in a Consolidated Edison power station.

The company has said power will be restored by Saturday to most of Manhattan, though customers in other parts of the city may have to wait another week or more to get their electricity back, and across storm-ravaged New Jersey many remain in the dark.

The storm, which killed dozens of people, also crippled transportation systems across the region, giving people fewer options over which friends to stay with.

PLENTY TO SPARE

Some of the largest and most expensive homes are located in the neighborhoods of the Upper East Side and the Upper West Side, on either side of Central Park - which means that there are plenty of resources to share.

But the commingling of family and friends, or even strangers and acquaintances - including people who may not have bathed, since there is no hot water downtown - hasn't been easy for everyone. Restaurants that were once calm and relatively quiet are now crowded and noisy.

Gyms and health clubs above the dark zone of Lower Manhattan have become half-way homes for those without power, hot water and flushing toilets. On Thursday, at least 20 members of Equinox Health Club at Columbus Circle could be seen sitting on the ground, grouped around power outlets, charging smart-phones, laptops and other electronics.

Even the Equinox employees are part of the migration.

"I'm staying with 10 other people right now in a room at the Trump Hotel," said an Equinox employee called Madison, as she handed out towels to the constant stream of gym members passing the desk.

On Wednesday, Equinox members received a blast email saying they were no longer allowed to bring guests to the club for showers. "As you know we've done our very best to remain open regular hours in all clubs with power," the email began.

"We are getting unprecedented usage and, in an effort to better serve our members, we cannot accommodate guests until the situation stabilizes."

Often it isn't just humans who have to be accommodated. Daniel Smith, 39, who had to evacuate his flooded West Village apartment, arrived in Manhattan's northern neighborhood of Inwood to stay with friends with his parrot Lola in tow. He worries that he isn't pulling his weight as a guest because he has spent each day since the storm cleaning his own apartment.

"I wish I had the energy to make dinner, but the best thing I can do is not fall asleep at the table," he said. "Usually I am a much better guest."

Raymond Lozanes, a 37-year-old consultant at software company Oracle, has three friends crashing in the living room of the one bedroom Hells Kitchen apartment he shares with his partner, Matthew.

Things got craziest on Tuesday when another five people came over for a few hours to charge their phones, have a meal and a hot shower. "It was an impromptu charging party," he said.

COLLEGE STUDENTS AGAIN

When it became clear the power outage was going to last more than a day or two, 39-year-old Jon Reinish, a native New Yorker living on the lower East Side, grabbed a bag of dirty laundry, packed up and went to his parents' apartment on the Upper West Side.

"I am sitting here putting out press releases, and my laundry is being done in the next room," he said. "It's like you become a college student again."

Mind you, staying at home has its own set of challenges. "I am leading my part of a 20-person conference call and my dad comes busting in to tell me I left the light on in the kitchen last night," Reinish said.

But as the days without power continue, both hosts and refugees are wondering how long is too long before the guests outstay their welcome. Steve Devera, one of the guests staying in Lozanes' living room has found another place to stay Thursday night and is hopeful his power will be back Saturday.

In another apartment in the same doorman-serviced building where Feld lives, Helga Shepard, who is 80 and a Holocaust survivor, let the leader of her book club come to stay after the power went out in New Jersey.

The woman spent one night on Shepard's couch and left.

"I've been asking myself - why did she leave?" Shepard said. "I'm pretty sure she knew I was delighted to have her." Shepard mused that perhaps it was her pet bird, a cockatiel named Amelia, who perches on her shoulder and "likes to run the house." (Editing by Martin Howell and Todd Eastham)

• A Permanent Economic Emergency