Thanks for those suggestions! Obviously I just wasn't looking in any of the right places.
We're looking for a 2-br place more than adjoining rooms mainly because the focus is really on the being together aspect of the trip, rather than being in New York. Not that we won't enjoy NYC while we're there, of course! However, I guess it's important to us to have a shared space to hang out in, rather than two smaller living spaces or having to go out to more public places like bars and restaurants to socialize amongst ourselves.
Normally we do more of a house party thing and rent a place, usually somewhere with more of an outdoor activity focus. NYC works best logistically this year though.