I know that you were mentioned that you were looking for backyards before deciding on a venue-
Have you looked at VRBO for vacation rentals with big backyards?
Like these ones?
http://www.vrbo.com/329800http://
www.vrbo.com/278292http://www.vrbo.com/260512http://www.vrbo.com/311992http://www.vrbo.com/191271I'm not sure where you are getting married though. But just an idea.
VRBO is a nation wide vacation rental site.
For anyone else that comes across this post- Have you known anyone that has used VRBO to find a venue?