How much magic do you want in your GoT?
5e can proceed very well without magic items, but the classes & races have access to a lot of magical effects anyway.
All classes have access to magic, for example: there's a type of Monk which can teleport all day. There's a type of Fighter who has cantrips and spells. There's a type of Barbarian which can commune with nature. And so on. There are zero classes which are purely mundane.
So. What would you remove, and what would be left?
Or would you allow full ordinary D&D classes?