My husband's cat, Smidgen, snuck out of the house one evening when the door had been left open for a fraction too long and was gone for eight long weeks. Smidge had been a house cat his entire life, and after a couple weeks I really didn't think he could have possibly survived, especially since he is front declawed. We live in a rural area heavily populated by both fox and coyotes.
We searched on a daily basis for a month, then a month after that we heard a pitiful whining coming from the drainage pipe in the ditch in front of our house. DH went to grab the flashlight, and sure enough, there was poor Smidgen, who would not have made it much longer for sure. He was very dehydrated, and skin and bones, but he's with us to this day and is a grand old man of 17 with no sign of slowing down.
I wish you the best of luck with finding your kitty.
Therese