Kittens In Distress

Unfortunately Benji is not happy now in the cage. He feels better and stronger now and started rubbing his nose on the metal parts and is openning the wounds.
He can see and hear the birds flying, my cats walking by and being an outdoor cat for many years, he does not like to be confined to a small place. He sits all the time and looks at the open door and meows.
I decided to take him earlier for the tooth removal, since nobody came forward to offer him a foster and sadly I will have to let him go, once he will recover from it.
I can not let him into my garden, as he would fight with my blind boys for sure. I tried to move him to the bathroom - equally hot now, but closer to me and he would have more space to walk - but he was so scared of being there, he was going under the sink unit to hide in the drawer.
I am not home all the time to make him used to be in different place. Benji obviously was lost or abandoned long time ago and is now used to live outside.
I feel he has a beginning of cancer in his nose. That corner of his nose does not look good, but injuring himself over and over everyday, will speed up the process.
He knows this area and I am sure he will be coming to eat on my fence again. I can monitor him and give him cortisone tablets for his skin and if he will start having bigger problem, then I will be taking him to the vet for pain relief treatments, but keeping him in the cage for the remaining time of his life would be cruel.
Now the storage is very hot, in winter will get very cold.
Benji is an old cat and is used to his ways. I am sure with someone having time and letting him used to life at home, he would be happy eventually, but it is not possible to find that person, so there is not much choice for him sadly.