Brandy DW
Missing Neka, Loving Sabriel, Nakaia, & Trance
You may find that is your choice... either the litterbox is hidden away down in the basement and your cat is too... or you deal with the litterbox in your living quarters...
The behavior down there might just be that it is quieter down there so she gets into a quieter mood...less stimulation to perk her attitude.
This I agree with, cat's (hybrid or not) respond to stimulation. Yes savannah's are more prone to finding entertainment, but maybe with the darker environment she's going into more of a hibernation mode? I know cat's don't hibernate but I hope you get what I mean..