Hi, The Gingercat stayed behind the couch, most of the time for around a month when he first came to live with us; I just let him take his time and gradually moved his food further into the room. Every now and then, about 3 times a day, I would drag him out, give him a real cuddle and pet and take him to the kitty litter wher i left him in private. most often he would fly like a bat out of H--- back to the 'safety' of the couch. He still goes behind there if he feels threatened by a stranger arriving at the house, 3 years later. I believe you just need to give him time to get used to the strange surroundings, let him decide the speed of adaption. I would certainly not fuss him too much. he will return to normal in time and he will eat when he gets hungry and he will certainly come out to use the 'facillities' he won't mess where he is at present sleeping/living. best of luck to you all in your new home.
Angie and The Gingercat