Regarding the practical dilemma of his ashes coming home, there are a couple different things you can do. And you don’t have to do anything right away, maybe wait for a beautiful spring or summer day when you’re more ready…
You can keep the ashes in a nice urn. They have small ones you can get for pets. My sister in law is law enforcement in Ohio, former K-9 unit. Her dog was an incredibly important part of her life. Not only was he her partner for her work with the K-9 unit, he was a pet as well. When he passed away, she displayed some pictures of him along with his collar and an urn of his ashes on a shelf.
You can also spread his ashes in a special place. If you are in your permanent home, you can do that outside and maybe plant some flowers, a pretty bush, or a tree in his memory. If you are not in a place you’re planning to stay, you might decide to put the ashes away until a time in the future when you are in a permanent place.