MIL’s 13 ES350 (215/55-17) will need new tires in the next 5-10K miles.
The current set of Michelin Premier A/S have been in-service for 5 years and 28K. They are between 4/32” and 4.5/32” remaining - rotated every 5K.
Service life really isn’t a concern. I prefer to replace tires every 5-6 years and she will only drive 30-35K during this timespan. Wet traction and ride quality are the main focus.
Cost isn’t a concern since I will likely receive a generous prorate credit on the current set.