by Pajarita » Tue May 19, 2020 10:58 am
Welcome to the forum! Well, the best way to make a parrot do anything is to tempt him with food so I think that if you put a bowl with a couple of his high value items in the 'other' cage and wait him out, he will, eventually go into it. Grays dislike changes and new things but they are also very smart and, if you give him enough time, he will figure out is safe to go into the new cage.
But, unless I misunderstood your post, having two cages side-by-side does not really offer him more room - it's like having two small rooms instead of a large one. When one talks about a species adequate size for a cage, it always means one LARGE cage... couldn't you take the two cages apart and make one out of the two by removing a 'side wall' of both and joining them together?