What to do about broken WiFi on iPhone 4S after iOS 7 update? Several iPhone 4S owners have noticed a problem with their WiFi not working after upgrading to iOS 7.

It appears to be both a software problem (our phones have been working for nearly two years with WiFi being just fine before the upgrade) and hardware problem (it gets partially better when the iPhone is chilled (physically).

My particular symptoms:

iPhone boots off spontaneously.
Diagnostics showing several panics with a debugger message of "WDT timeout" or "panic" listing kernel_task as the panicked task.
WiFi switch is disabled and set to "Off", can only be enabled by refridgerating the iPhone and rebooting (possibly needing to reset network settings).
When WiFi can be enabled, it repeatedly drops the signal.
If the iPhone isn't cool, Settings freezes up in the WiFi settings and, to a lesser amount, in the Cellular settings.
Once the iPhone warms up, the problems begin anew.

So the question is what can we practically do now? Is there any use calling Apple support (for out of warranty devices), should we take it in to an Apple store (for a not-too-expensive repair), should we take it to a local phone reapir shop (is this the type of thing they can repair and what does that usually cost/how long does it take), is there any reason to expect a software fix, or need we basically resort to exchanging our phones in for new ones?
I say give Apple a shot. I've been successful in resolving similar upgrade issues by calling the support number or making a Genius Bar appointment.

Local repair shops are fine for fixing a hardware component (i.e. replacing a screen) but not much help for an iOS software problem. Also see ifixit.com for DIY hardware repairs. They are amazing.