Rosemary can't handle this request in combination with your wedding? I would think this will be hard to find outside them - set up, etc. for that many people for a 2 hour event. You might want to contact Camp Helen just down the road from Rosemary. I have been to a cocktail event there. Beautiful location on Powell Lake.
Just remembered Eden Park for meet and greet. Beauti of a location.
Ceremony and reception are at Rosemary, so dont want to have the cocktail reception there too. Would like to kind of show off the area to out of towners. Thanks for the Camp Helen tip though. That sounds like potential.