Much the same experience here. On 29 October 2021 my 2015 S85D was towed to the Palo Alto, CA service center with a failed HV battery. The battery is covered under the 8 year warranty. So far there is no word on when a replacement battery might be available. The service experience, while civil, has been unsettlingly free of much information or apparent enthusiasm for solving my problem.
I foolishly declined a loaner at the outset and now find myself on some sort of waiting list. My patience is wearing thin and I'm considering next steps. The California Lemon Law can apply to vehicles unable to be repaired after 30 days but, generally, ones less than 18 months old. This car is 6 years old so likely an uphill battle.
--Frank.