We get these questions pretty often, and the answers are always along the lines of: probably, maybe not, but it'll almost certainly be worth going anyway.
Objectively it's a weekend that would be prime for big crowds since it's a three day weekend and it's the last hurrah of summer. However, sometimes enough people avoid the park on supposedly "big" weekends that the crowds turn out to be OK. Plus if there's any hint of rain the park could very well end up deserted.
