"There’s zero plot really in that movie anyway, you could do anything and call it a sequel," the actress joked. "Anything [at all] and just have that group of people… [and] I would do it in a heartbeat."
In the 2008 farcical comedy, Hahn plays Alice Huff -- wife of Adam Scott's character, Derek Huff, and sister-in-law to Ferrell's Brennan Huff -- who begins a wild, off-kilter romantic affair with Reilly's Dale Doback.
Directed by Adam McKay -- who previously brought Ferrell and Reilly together for the 2006 NASCAR comedy Talladega Nights: The Ballad of Ricky Bobby -- the film featured elements of heavy improv from its entire cast, which was a relatively new experience for Hahn, at the time.
"That kind of broke it open for me as a performer, working with those guys," Hahn recalled. "I mean that was a real anarchic moment for me. I was like, 'You can do this on camera?'"
This video is unavailable because we were unable to load a message from our sponsors.
If you are using ad-blocking software, please disable it and reload the page.
Watch Mila Kunis, Kristen Bell and Kathryn Hahn Take Over 'The Price Is Right'!
The star explained that shooting that film, with that cast, was a "turning point" for her as an actress.
"I didn’t know you could improvise like that. I didn’t that you could be that lawless. I didn’t know you could throw the script away like that," she shared. "It was the best."
As for where she could see the characters in a possible sequel, Hahn said it would "have to be something to do with Catalina, because I think it’s such an iconic part of that movie," referring to the film's hilarious comedic crescendo at the Catalina Wine Mixer.
"[And] I feel Alice is in jail somewhere," she added, referring to her own over-the-top character.
In Hotel Transylvania 3: Summer Vacation, Hahn stars as Ericka Van Helsing, the captain of a luxury cruise liner who is also the descendent of famed vampire hunter Abraham Van Helsing. When a Dracula (Adam Sandler) falls for her during his family vacation, she secretly plots his demise. The animated sequel -- also starring Selena Gomez and Andy Samberg -- hits theaters July 13.