If you have the space, it can be an idea to let them have a play in the new cage, the day before moving. With substrate in it and one or two things in there, like a tunnel and a hide or a familiar thing from his old cage. Then when you actually move them over it's already a bit familiar and has their scent (especially with all the old bedding on top). I find that works well for Syrians anyway and helps them settle in a lot quicker.
Having said that, if you're moving all his old bedding over anyway and keep a similar kind of layout as much as possible (eg house on the left, wheel back right or whatever), that also helps them adjust quicker too.
It can take a week to 10 days for them to feel fully settled in a new cage though. Initially they are loving it and exploring and then a slight panic can kick in when they realise they're not going back to their old familiar cage. But they usually adjust within a few days, sometimes a week or more.
For that reason I completely remove the old cage from the room after they've moved to the new one - because they can still smell it! And it can bother them a bit.
I expect you're waiting for the wheel before moving him though?