I have posted many times on this topic. My SIL is DOOGOO, Director of Operator at the Grand Ole Opry.
The weather is fine, although I can't give you an exact forecast for next May.
The schedule for the GO will not be known until close to then. Here's their site:
http://www.opry.com/
My wife and all the
girls in her family go at least twice a year, summer at Fairfield and Holidays at a hotel, probably Opryland this year.
Their stay at the Fairfield this year was not all that satisfying, and you can probably find that thread with the search feature. First week of August.