Christian Siriano (left) and Brad Walsh
Christian Siriano is known for his flashy fashion, so he'll be wearing something extra fierce on his wedding day – right?
"We have, like, no plans yet," the Project Runway
winner told PEOPLE at Moët Chandon's 270th Anniversary party in New York on Tuesday. "I haven't had time with planning [my upcoming] collection – I know, it's really sad."
The designer and his fiancé, recording artist Brad Walsh, exchanged Saint Laurent engagement bracelets in July – and Tweeted photos
of their newly accessorized wrists – but have decided very little about their upcoming nuptials.
But Siriano has come to one realization already: size matters.
"We want it to be small and intimate, but I don't think it will be," he says. "It's always about the guest list growing and growing – that's the exciting part!"
So who's in and who's out? No word yet on whether or not his good pal and client
, Project Runway
host Heidi Klum
, will be in attendance, but she did send her congratulations on Twitter
And though he's focused on designing rather than planning a wedding, Siriano is sure he and Walsh will make it work – eventually.
"Listen," he says, "we know everyone in the world. It will not be hard."