Making way doesn't mean being empty. Nobody arrives at a new relationship as blank space, and the ones who appear to have managed it have usually just hidden the boxes better.
There is a spare room in a lot of houses that is technically full — a bike, three suitcases, the exercise machine nobody uses. It can still take a guest. Somebody spends an afternoon shifting things and the room turns out to have been available all along.
Room for a new person works like that. Not a vacancy. A willingness to move some things, and to let somebody be in the house without being measured, hourly, against whoever used to live there.