Lucky Henry, to have two guardians to take care of him. I've had several cats live for years with this condition, even without going on a special diet - though I used subq fluids which helped enormously. However, I just lost my Nougat to CRF only weeks after she was diagnosed, which really shocked me after the others had lived so long. As you said, it can go either way. We will all hope for a good few extra years for Henry.

Has your vet suggested Epatikin? You sprinkle it on their food and it helps bind excess phosphorus. Will you give subq fluids?