The mood in the Beverly Hilton’s International Ballroom was bittersweet as the producers and key cast members of “Downton Abbey” took the stage over the weekend for what was to be their last time at TCA. Series 6, as they call it in the U.K., will finish taping Aug. 15, and the smash-hit period drama will air in the U.S. beginning in January 2016 on PBS “Masterpiece.”

It’s difficult overstate the importance of “Downton” to the public broadcaster — or the devotion of its legions of fans worldwide as it heads into its final season, set in 1925.

“Oh dear, this is our final time,” said “Masterpiece” executive producer Rebecca Eaton in her opening remarks. “What a gift to have this show and what an incredible boost it has been to “Masterpiece” and to PBS in general. It’s going to be hard to say goodbye.”

She gave an overview of Season 6, which has Lady Mary taking a firmer hand in running the Crawley estate and Lady Edith continuing to run her own company. Then, she cued an exclusive yet brief preview of scenes that depicted Lord Grantham and his butler Carson discussing downsizing the help at the estate and Grantham, man of the manor Robert Crawley, delighting in using a new invention, the refrigerator.

In addition to executive producer Gareth Neame, actors participating in the panel included Hugh Bonneville (Robert Crawley), Laura Carmichael (Lady Edith Crawley), Michelle Dockery (Lady Mary Crawley), Joanne Froggatt (Anna Bates), Elizabeth McGovern (Cora Crawley), and Penelope Wilton (Isobel Crawley).

“Her journey has been huge,” said Carmichael of Lady Edith. “She could’ve been the most conventional of the three daughters but she’s had to find a different path and I’m delighted by the direction. She’s incredibly resilient. In this era [the 1920s] there are windows of change. Her journey is so specific to the time.”

Wilton was asked about working opposite the formidable Maggie Smith as Violet Crawley, the dowager Countess of Grantham, with whom her character tangles on a regular basis.

“I’ve enjoyed immensely playing opposite her in the fractured yet affectionate relationship,” she said. “Julian [Fellowes] sometimes allowed me to beat her. I’m constantly frustrated by her wit. One of the reasons we get along is we started in the theater and you get used to a way of playing. I enjoy every person in this company. It makes the rhythm of writing go very well.”

She also noted that Fellowes, the creator and writer, doesn’t want the actors to change anything, while Froggatt mentioned that after casting, he adapted his scripts to play to the actors’ strengths. And some additional trivia from Dockery: Branson, played by Allen Leech, was originally a small role and he was not meant to be Irish.

“Downton Abbey” premiered on ITV in September 2010 and on PBS in January 2011, set nearly a full century before, just as the Titanic sank in the North Atlantic Ocean.

The actors were asked about what they enjoyed most from that era, and what they learned from it.

“I miss the peace of it,” McGovern said. “Today we are so inundated with information — stuff we don’t need to know. I miss the peace of the world where everyone knew their place and life seems so quiet by comparison. Today you know every party everyone has ever gone to before you meet them. It’s more than you can process. In Downton, we know our circle, and how to behave. There are limits but it’s peaceful.”

“I’m lucky to be living in a free society,” Froggatt said. “That’s stuck with me.”

“You had fewer things, but when they were made, they were tailor-made. I enjoyed the hats,” said Wilton.

Elements of humor crept into the discussion.

“I learned that only people who smoke cigarettes are up to no good,” said Bonneville.

“I’ll miss the clothes,” Dockery said of Lady Mary’s gorgeous gowns, to which Froggatt replied, “I won’t miss mine” about her servant’s garb.

Most of the questions centered on the ending of the beloved series, including what the actors would want to take home from the set, especially from Highclere Castle, which doubled as Downton.

“I’d like to take Lady Mary with me — and Mr. Bates,” said Froggatt.

“I’d like one of the mustard pots from the dining room,” Bonneville said.

“If I can have the person who arranged the flowers coming to my house,” said Wilton.

The actors, most of whom, except for McGovern, were unknown in the States before “Downton” blew up, also talked about the platform it has given them promote and raise money for their favorite charities, including World Vision, WaterAid and Oxfam.

Here’s what the cast announced as their next projects:

Bonneville: Lord Grantham will soon play Lord Mountbatten opposite Gillian Anderson in the film “Viceroy’s House,” shooting shortly in India.

Froggatt: Servant Anna will transform into the real-life serial killer Mary Ann Cotton in the Victorian-era ITV drama “Dark Angel.”

Dockery: Lady Mary will play Letty Dobesh, a thief and con artist just out of jail on TNT’s upcoming “Good Behavior.”

Wilton: The actress who plays Isobel Crawley said she’ll be shooting in Ireland, but couldn’t reveal details of the project.

There remains speculation about a “Downton Abbey” movie, of which Neame said there’s no script or plan, but let it appear the door could be open. After all, there is a two-hour Christmas episode that has aired each year the series has been on in Great Britain.

The executive producer is more concerned with going out at the optimal time. “There’s no question we could’ve done seven or eight [seasons],” he said. “ITV or PBS did not want to cancel. It’s about leaving a bit earlier than you might have. No one goes into a TV show expecting to be there six years later. But five would’ve shortchanged a global audience. We may be leaving a bit early — but on a high note. I want you to watch all of it, and then go back and watch it all again.”