Still no sign of Nyx in the house. Food, water and kitty box, untouched over night. No recent suspicious noises.
I have asked my human neighbors if they have seen her, in case she did somehow get out, with no luck.
Unfortunately, the non-human neighbors include eagles, hawks, owls, and coyotes, one neighbor has mentioned seeing a bobcat on his trail-cam, and I think my birdfeeder was taken out by a bear.