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(Jemal Countess/Getty Images)

Olivia Wilde, who is engaged to "Saturday Night Live" star Jason Sudeikis, has big ideas about her wedding - though she can't seem to figure out the details.

"Anything you heard [about timing] is a lie because we don't know yet!" says the actress, 29, who is making the rounds at the TriBeCa Film Festival promoting "The Rider and the Storm," a 15-minute documentary about a Queens iron worker whose beach-side home was destroyed by Superstorm Sandy. (Wilde is an executive producer for the project and her friends, RYOT.org co-founders David Darg and Bryn Mooser, shot and co-directed it.) "We're so blessed to be very busy at the moment, but it will be fun whenever it happens!"

While she does have her dress designer nailed down ("Monique [Lhuillier] is making my dress and my bridesmaids' dresses, which is very nice," she said), picking a location has also proven to be tricky.

"We think we should get married in Uganda," joked Wilde. "[Darg and Mooser's] next film is in Uganda, so in order to have them at the wedding, I'm going to have to follow them where they go." (One perk to this possibility? Her videographer would be set: "We're shooting it!" Mooser offered.)

Her mother has another idea, said Wilde: Haiti, where "The Incredible Burt Wonderstone" star volunteers with her film-making buddies.

"It would be great, but we're like the only three people who would [like to get] married in Haiti," she said. "No one would show up! [I'd say], 'What do you mean you're unavailable?'"

Plus, there would be aesthetic issues.

"When I'm in Haiti, within three seconds of getting off the plane I am red-faced, usually broken out and really sweaty," she admitted. "It would be a red-face, acne wedding."

All kidding aside, the actress, who said that no matter what, her wedding will be "great," is clearly smitten with her fiancé - and the vintage diamond-and-emerald ring he gave her.

"It's from the 1920s," she said of the sparkler, which Sudeikis picked out on his own. "I think when buying stones, enough of them exist in the world, so there's no reason to be buying new diamonds. I love it."