1. I have the same Wi Fi greyed out, fast battery drain iPhone 4S 6.0.1 problem, which started about two weeks after I got the phone as replacement for my original phone that had a different battery drain problem (under warranty).
2. I read through much of the threads about this problem
3. My conclusion is this: Apple has a serious quality assurance problem with these phones. The problem is not IOS related. It is a hardware issue. Possibly with the WiFi chipset. All these tricks of Hair dryer/ Freezer etc. point to a hardware issue. Until Apple revises the chip and/or finds a way to test these chips for this problem, it will not go away. It is not a simple problem since the bug seems to be a soft error related problem.
4. We are screwed, because, even if Apple exchanges our phones, there is no guarantee the problem will not come up again.
5. I am sure Apple knows about this, still has no solution, and is afraid to admit it.
6. Sell your Apple stock before it tanks.
7. Go buy Samsung.
p.s. If you really want your Wi Fi back even for a short time, the Deep Freezer trick works. Just shut your phone off and let it cool in the DF for 30 minutes. Presto! Wi Fi is working again. It will stay alive for a few hours to a few days and then it will get stuck again. Only do me a favor, and dry off your phone with a warm hair dryer as soon as you get Wi Fi to work, to make sure you do not get condensation inside.