Yes, I've done it before and I would do it again in a second. I had a diabetic cat for three years. He did wonderfully on twice daily insulin and also every other day fluids to combat kidney failure. Did he need or deserve to be put down because of his illness? Heck no! He lived a wonderful life because we took care of him. It meant that one of us had to be home at 7am and 7pm, but we did it. We went out to dinner earlier, if we had a wedding we ran home between the ceremony and reception, etc. We made it work.
ETA: We were still able to vacation regularly. Our vet was actually a neighbor and he came to the house morning and night to take care of the cat. We only got stuck once. I had taken my grandmother to buy a new car and it took longer than expected. My father wouldn't give the insulin, so he called my next-door neighbor (a nurse) and she agreed to give it.
ETA: We were still able to vacation regularly. Our vet was actually a neighbor and he came to the house morning and night to take care of the cat. We only got stuck once. I had taken my grandmother to buy a new car and it took longer than expected. My father wouldn't give the insulin, so he called my next-door neighbor (a nurse) and she agreed to give it.