Hi,
We (my son and I) just had a similar experience. We lost our bearded dragon, Bob, for 8 weeks! We were sure he was dead the day he escaped from his outdoor enclosure because the weather was turning cold (20-30 degrees at night). I was devastated. I thought I saw a ghost the other day when there he was in the garage staring at me from the bottom of our wood pile. I screamed - it was unbelievable to find him alive. Like Bo, Bob seemed like he hadn't missed a meal and didn't seem dehydrated. BUT, he sure got a taste of the wild! He goes crazy in his cage now, standing up and pawing at the glass for an hour at a time! We take him out a lot, to hold him and to let him walk around inside and out with careful watching. He also has a spot on the windowsill where he like to sit and stare out the window. But he is definitely a changed man from his excursion.
Does anyone have any ideas about how he could survive in that cold for 2 months? I guess he was hibernating, but by the way he acts, it seems he was running around. When we let him out now he is FAST! We are so grateful to have him back.