Calling home when I arrived in London, New Yorkers said, “Lucky you’re in England. It’s cold and rainy here. How is it there?” I said, “Cold and rainy.”

Whether it’s cutesy Prince George keeping a smile on or randy Prince Harry keeping his clothes on, the mother country’s spirits, like its prices, are high.

While America’s reporting my friend Joan Rivers’ tiff with a Norwegian cruise ship line known for its sardines, happens that we’re together here for a few days of R&R. Seeing plays, seeing friends. Her E! TV show “Fashion Police” is so hot locally that the woman’s a queen on the bank of the Thames. When she walked past Balmoral — in sequins and rhinestones…and it was early morning — even the Beefeaters bowed.

We did afternoon tea at Highclere Castle, where “Downton Abbey” films February to July. Its in-house resident, Her Ladyship the Countess, showed some of the 300 rooms, including where Lord and Mrs. Lord Grantham slept, where Shirley MacLaine dressed, where — I noted — a 17th century bedroom, complete with chamber pots, held a Vanity Fair copy plus a book on Piers Morgan.

Also where, minus a library card, we checked Highclere’s 6,500 books, including an 1800 handwritten Koran. And examined Napoleon’s actual desk. I mean, we are not talking no Ikea here.

She also admitted the castle is haunted. Kindly note, we didn’t houseguest.

Ours was a look into history. A private Churchill War Rooms tour inside the Imperial War Museum. His safe sleeping area during air raids. His favorite red velvet jumpsuit. His private locked cupboard, which hid wartime’s rare treat — bananas. All clocks read 5 to 5. That’s when, on Oct. 14, 1940, No. 10 Downing St. was bombed.

We saw one daily chart of enemy planes: Destroyed, 183; Damaged, 75; Probable, 42; Pilots safe, 28. It was when a mighty country pulled together because the fight was right.

And then it was luxury in the heart of Piccadilly Circus, Regent Street’s glorious new 21st century hotel, the Cafe Royal, which was built around a landmark, the Edwardian heyday’s famous Cafe Royal restaurant. A onetime favorite of King Edward VIII, now a favorite of Joan and me, her lady-in-waiting.

Suites come with your own private butler. Evenings, go to the Oscar Wilde Bar, a gilded salon formerly known as the Grill Room, where Queensbury rules were created. The frescoed homage is restored to its original Louis XVI detailing. And if you’ve too much Champagne, there’s the Akasha holistic spa’s pool, massages and meditation rooms.

We also knocked off a few West End shows. The Duke of York’s Theatre billed “Jeeves & Wooster” as “perfect nonsense.” Yeah…believe me…what helps comedies here is allowing drinks at your seat. Trust mother, kiddies, a good belt of booze and “Moose Murders” would still be running.

Then, again, more history than my sixth grade teacher stuffed into me. The play “Handbagged” piggybacks between Queen Elizabeth — the familiar tight coif, tight lips, white gloves, black shoes and schlepping the usual purse from her wrist — and Margaret Thatcher. The audience lapped it up faster than kidney pie.

Saturday, a double header. The Royal Shakespeare Company’s “Wolf Hall” at James Nederlander’s Aldwych Theatre. More English than the Tudors, it’s the 1500s, Henry VIII, wife Anne Boleyn beheaded because she was bad, bad, badder than Leroy Brown. She should have nailed a prenup, a house in the Hamptons, more bread than Silda Spitzer, and enough for lifetime botox. Stupid bitch.

Evening, the Almeida Theatre in Islington. “King Charles III.” About Camilla’s hubby being His Majesty, plus HRH William, and commoner Duchess princess semi-queen Catherine and dark images of Diana swanning around swathed in black. It’s Chuck doing a to-be-or-not-to-be-a class-A monarch and finally yielding the throne to Prince William. Interesting, yes. Load of laughs, no.

Local chat is, “Kate was smart…we knew she’d nail His Royal Highness…when they broke up and then reconnected at a party, she behaved properly, never spoke to the press, never gave interviews …always played him right…and her smart mother made her change schools to go to his…we all knew she’d seal the deal.”