My husband with dementia (MHwD)(88) no longer drives; car is in both his name and mine. Should I renew his license (for ID) and do I need to change insurance to say that he's no longer driving? Or should I take his name off the registration (which would necessitate insurance change)?
Yes, take his name off the insurance as a driver.
If his name is on the car title as “and” I would also take his name off of it.