cats are super adaptable, you can amputate on leg without any problem for recovery. i had to make a choice a couple of years ago between cutting my kitties front leg or letting her die of cancer, and now she is super lively and jumpy. i had to give up my pocket money for the year before to convince my parents to let her live (the ghouls) but that was possibly the best use i made of my money in my life yet.
Watching feel-good animal rescue videos on Youtube has really opened my eyes to how well animals can adapt to various mobility issues! I saw one with a pitbull who was missing both front legs - she still bounced around like a happy little rabbit. I actually find it really inspiring, in a weird way. I lost my childhood cat to cancer - I'm happy to hear your kitty recovered so well :)