I have another dog cage. I am going to set it up in the living room so that the dog can get used to having Honey around. Honey will only be in there when I can supervised the situation. If the dog gets too excited around Honey, I will squirt her with a water gun. That is sort of how I trained her to be around the cats. With the cats, I kept the dog on a leash in the living room, and when she got too excited around them and displayed her hunting instincts, she got it with the water gun. Then there was a lot of praise and treats when she was calm around them.
Finding room for rabbits to run in the house has always been a problem. That is one of the main reasons most of my rabbits are outside. My hutch bunnies have large covered runs, and a more mentally stimulating environment. There is also a problem with family members and allergies, but meds seem to be keeping that under control for now. That could change once I allow Honey to spend more time in the living room.
I do have a pet playpen, but those playpens aren't much bigger than the big dog cages. Maybe if I keep exposing him to the kitchen floor, he will get used to it. I do have a few rugs I put down, but he just sits under a chair. I am taking my time to acclimating him to different things in the house, I don't want to stress him out too much, so I am doing things in little steps. I worry that with his allergy problems, his immune system might be compromised. Right now he is getting used to my cats, and they are getting used to him. They are both afraid of each other, and very curious. Honey may not have a lot of freedom, but I am sure he feels safe. More freedom will do him no good if it comes with added fear.