I have been in the woods on the Appalachian Trail in Tennessee and Virginia. I hiked up onto a ridge and followed the trail for several days before descending and leaving the Trail in Damascus, Va. I had little to no cell signal and in any case, only turned the phone on once a day to make a check in call so I could preserve battery life.
It was fairly cold, below freezing a couple of nights, and it tested the gear I had brought but it all worked out fine. The days were clear, the hiking was not too strenuous after the first day's climb, and my old body seemed to hold up to the challenges.
Here's some pictures of the week. Click on them to see them full sized.