Wow! Way, way too many comments about loans, etc. Back to the “battery fail” topic from the OP:
I’m no expert but enjoy reading explanations from wk057 and others which all say that, absent something like salt water flood damage, entire batteries do not fail; rather, a small component in a single module fails which shuts down the whole pack.
I can vouch for ce2078’s excellent work repairing packs, upgrading to larger packs, fixing eMMC, etc. I have seen his cars and others he has worked on and have been impressed, especially because his charge (sorry, couldn’t resist the pun) for pack repair is only a tiny fraction of Tesla’s estimate. Even if you add in the cost of transporting your car to him, it would only increase from a tiny fraction to a small fraction.
You might also have him proactively fix your eMMC as long as your car is there since you are out of warranty on that part as well.
Please let us know what you choose to do and how things turn out. Good luck!