If this is available with a 5-day minimum for base GP members, then they must be making it available with the "Diamond Room Availability Guarantee" for the 2-day reservation that you are looking for.

I really think you are expecting too much of Hyatt to make Diamond Guarantee rooms available as awards. Hilton is the only program that does this, and even then it is NOT a published benefit and sometimes takes a lot of prodding to be able to do this. And IMHO that is about the only redeeming quality of the HH programs, otherwise HH Diamond sucks!!!