Here's a smarter idea: assuming you cant go after the current/former vendor (perhaps because they told you the usage specs they were built to, but you ignored them?), SCOUR THE MARKET for a new one.
Knowing the approximate size of the needed MCU replacement set, plus future S and X builds, place a mega-order with the new vendor with correctly temperature-certified parts, and a strong "warranty returns" contract so Tesla won't be screwed again. Surely someone will want the business and can come to the table with a good offer given the size of the order?
From my eyes as a long-time Tesla owner, this is the best solution, and far, far better than wasting money on fighting arbitrations that just make Tesla look both stupid and cheap--which is a really bad look.
Get someone on this STAT please.
He doesn't give a *sugar* about the S. This design flaw has been known for years.