Yeah 17 is pretty decent age for a cat. Especially one with diabetes, and who has had advanced kidney disease for a few years now. This one has always been our expensive one for vet bills. We have two cats that are 18 as well. When me and my wife were dating we each had a cat that was about a year old. We also each got a kitten to keep our existing cats company when we went to see each other. (Our dates lasted all weekend because we lived 4.5 hrs apart). All 4 have lived to a good age. (The other 17 year old lives with my parents now).
My parents really liked that one cat, and when we temporarily moved into an apartment when moving cities before house was built could only have 2 cats in the flat. I left him with my parents on a temporary measure but never took him back.
With friends in Atlanta but came back. My parents live on 3 acres and their house backs up to fields... Didn't seem fair to bring him back, he loved it, and he loved not being with our other cats. The one that was in Atlanta was in a house with a dog that he never got used to and was much more social with the other cats. With him I'm sure it was a relief to be reunited with us.
Yup. We did that too. Fortunately he really didn't seem to mind. Just a pain going on holiday trying to get someone to come by a do it... ... And then they inevitably leave the solution out of the fridge so it goes bad.