Not callous at all... He’s a really old cat, and the end was going to come eventually. I’d actually rather he pass peacefully now than have him linger for days, it would be a relief if he did. He had a good life, I’m at peace with it. If he’s still here, and like this tomorrow, we’ll probably take him in and have him put down.
I believe you are making the right decision. The way you have him set up right now is very good, he’s confined and no one can bother him.
He looks comfortable.