I am so sorry for Pouncer.
But I don't think it is already the end: first they have to do something against the blockage and the sub-qs are for the renal failure. These are basically different things. With renal failure, cats can survive well for years- look at Fluffy, Filou, Puddy and many others.
They need regular sub-qs- but most cat owners can learn to administer them at home. Even the wiggleworm Filou who goes to see the vet once a week got used to them.
Look at the website www.felinecrf.com

I can understand you are just desparate of sorrow but there are chances for Pouncer