On the eve of her 90th birthday, with her lavish party plans kaput, Cindy Adams gives New Yorkers a master class in how to survive a lockdown with your sense of humor intact.

Instead of sitting on a red and gold throne, wearing a 24-carat gold dress, entertaining 500 celebrity friends at the party of the decade Friday, Adams laments that she is schlepping around her apartment in a schmatta, cleaning up pee off the kitchen floor from her “new Yawkie” dog while her live-in Guyanese housekeeper keeps wanting to make her goat curry.

What would her late husband, comedian Joey Adams, make of it all?

“I remember on my 21st birthday, Joey gave me a full-length chinchilla fur coat with a diamond bracelet in the pocket,” she says. “And this year, I’m going to stay home in a schmatta.”

The baggy outfit was a gift from Dr. Daniel Baker, plastic surgeon to the stars, and also to the Saudi Arabian royal family. He had 25 Middle Eastern galabeyas made for her in Egypt and they have become her go-to attire during the lockdown in her Park Avenue penthouse.

“I was given a chinchilla and a diamond bracelet. Now I am wearing a long, full-length white schmatta, my brown charming hair now has a white ruff around it like Santa Claus, and my nails are all broken. I have one in the middle, which I’m now using to spear food.

“My big thing this morning was my dog peed all over my kitchen. So, my dog is 6 months old, does not yet have his manners. And instead of preening over 500 people on my guest list, I am wiping up dog pee on the kitchen floor.”

Her column hasn’t skipped a beat during five weeks “blockaded at home.” The phone still rings with tips as she taps on a laptop in a study festooned, wall and ceiling, with her 500 New York Post front page scoops: “WOODY’S BEING FRAMED!” “DI’S DRIVER WAS DRUNK!”

Last week, she wrote about sitting around watching old movies, like the rest of us. Only this was “The Apartment,” starring her friend Shirley MacLaine. “I then called Shirley,” she wrote.

Hilarity ensued, another gift from a bulging contact book, curated over the four decades she has written for The Post.

A one-time Miss Bagel, biographer of Indonesian President Sukarno, confidante of presidents and cardinals, best friend of Judge Judy, she is wistful for her city.

“New York to me is my religion. I’m a devout New Yorker. I have been all over the world … to Siberia, to the outback, to the Galapagos, and there is no place in the world that I would ever live but New York.

“However, when you look at it now, it is a ghost city,” she said.

“When I look out now, usually we can’t cross the street. Now, there’s only one person on a bicycle.”

Her building has emptied out and friends have decamped for the Hamptons or Florida.

Has she thought about how the city will be after the virus?

“I don’t think it will return the way that it was,” she said. “But will New York come back? You’re never going to make New York in Colorado, honey. And there ain’t no one rushing to Milwaukee, either. So eventually, it will be New York. But it’s not going to be in a hurry.”

Her party was to have been in Hell’s Kitchen in a grand space festooned with her front pages and decorated like Central Park.

There would have been original 1930s menus from Schrafft’s and, for dessert, Gristedes owner John Catsimatidis had found her 500 boxes of animal crackers to serve with ice cream in Dixie cups and a wooden spoon.

In the center of every table there was to be a huge tureen with 1930s penny candy, chocolate kisses, licorice and bubble gum.

The waiters were to be dressed as old-school newspaper men with little press passes in their fedoras, and Cindy would preside over it all from her red and gold throne.

“There was no limit to what I was going through with this particular birthday show. I have spent a fortune on this. I cannot begin to tell you.”

Her friends feel sorry for her, so they’ve been sending over gifts.

“Randy Levine, president of the Yankees, sent me a huge cake from Goldbelly. His wife, Mindy, she sent me steaks from Omaha. Francine LeFrak sent me a fish. A foot doctor called Rock Positano, he sent me a bottle of wine.

“So instead of a throne and dining with 500 people including — I’m not saying that they had said yes or no yet — the president, our mayor, our governor, our cardinal . . . Instead, I am having a cake from Goldbelly, a steak from Omaha, a raw fish and a bottle of wine, all alone with my housekeeper who’s going to suggest I have goat curry. That’s her idea of a birthday event.

“Oh, well, you can’t plan everything. Life throws you curveballs.”

So we leave Cindy, at home in her schmatta, wisecracking all the way to 90, and we just know New York will be OK in the end.

Swipe left on Fauci’s app-alling advice

What the hell was Dr. Anthony Fauci thinking when he gave the wink to Tinder hook-ups?

On a Snapchat show aimed at young people, the nation’s health czar was asked what advice he would give to someone considering “swiping on a dating app like Tinder or Bumble or Grindr” and inviting a stranger over.

Fauci was astonishingly insouciant: “If you’re willing to take a risk, and you know, everybody has their own tolerance for risks … If you want to go a little bit more intimate, well, then that’s your choice regarding risk.”

On his advice, the country has been shut down for five weeks, 17 million Americans have filed for unemployment, businesses have closed that will never come back.

Yet the White House pandemic adviser, who once told us we may never shake hands again, now gives a wink and a nod to sex with strangers.

It’s irresponsible and makes you question his judgment on other matters.

Cold, cold Nancy

Nancy Pelosi is the Marie Antoinette of the global pandemic. She sits in the kitchen of her San Francisco mansion in front of her $24,000 Sub-Zero refrigerators, showing off a freezer drawer stuffed with $13 ice creams, while businesses crash and millions lose their jobs.

“Let them eat Jeni’s Splendid Ice Creams” is her message, as she stalls the small-business relief package, the Paycheck Protection Program, unless she gets to fund her irrelevant pet projects.

She says of small businesses, “They will have more money as soon as we come to an agreement.”

They can’t wait. Doesn’t she get it?

Then she has the hide to go on “Fox News Sunday” and grade President Trump an “F” for his handling of the crisis.

This is the woman who urged people to come out to Chinatown en masse on Feb. 24. That was two weeks after Trump banned flights from China, and she was trying to make some point about racism.

It’s never about the American people with Pelosi, just petty one-upmanship.