Jason, thank you. I refuse to give up hope as well. Every time I go for a walk I keep calling "Missy, Missy" hoping that she will just happily emerge from a bush or whatever.
I used to walk RIP Madame Patches for up to 1/2 mile and she walked with me happily like a dog. Missy never really ventured out beyond our property but with the crazy warm weather here I think that maybe she got adventurous enough to suddenly go wild and maybe can't find her way home. I will keep you posted