**snip**
Sorry to burst your bubble here, but unless you flash the BIOS to do your overclocking (which is a pretty obtuse way of doing it considering how many free overclocking/overvolting software tools are available), then they have no way to see what you've been doing. There are very few non-volatile memory chips on a graphics card, and they are all used for boot-up and initialization processes.
This is even more true when you consider what it is we're talking about happening. You're trying to say that in the micro-seconds prior to your card dying (in some way, be it gpu-die, memory-die, or power-supplying hardware related), the device just saves the previous settings and then kicks the bucket? I'm sorry, but paying for an "overclocking" warranty sounds to me like being taken for a ride. It might be quicker for you to walk in and swap the card out, but the speed of hardware replacement is all you're paying for.
You have it set right so when you turn it off and turn it back on the settings are still the same correct it does not reset it on you so sorry to burst your bubble it is setup to save your previous settings.
I hate when people write things and yet do not know what they are talking about.