Already on order from the new guy making them.
. (I see you're on the GM-Volt website as well
)
We got the car back last night and sure enough it was completely covered under the warranty, $0 due. I plan to drive it up until the point that the Voltec warranty is nearly expired before installing the sensor bypass - I want to make sure the code doesn't come up again indicating it may have actually been something else.
As for having the sensor overridden, apparently even if there is a legit battery coolant leak the temperature sensor in the battery will also halt charging the same as the problematic bottle sensor, so in the end it's somewhat irrelevant except for eliminating a common failure point.