I'd say he's making the very most of his ninth life, fair play to him! Borrowed time, Laurie... But the renal food is helping and if you can do everything possible to maximise his fluid intake by encouraging him to drink and feeding wet food, you'll hopefully get the last 0.005% of renal capacity.
He is lovely. He has so much attention from us all as he's our last cat.
Our dog died at Christmas and we have a friends dog staying this week and the cat has remembered that he liked to walk to the end of the road in the evening for the dogs last constitutional with DH and then race them home so he could yell outside the front door.
Cats don't read text books. They are notorious for ability to defy clinical norms. As one lecturer at college told me just when you think you have feline medicine licked you meet an overweight, lethargic, anorexic and silent hyperthyroid cat.