Okay.
Suppose you have a sun and its planet in orbit.
At Spring, Summer, Autumn, and Winter equinox/solstices, you have the planet essentially at North, South, East, and West of the sun on a 2d grid.
Let's call these points in a 2d Cartesian grid: North/Spring: 0,5. East/Summer: 5,0. South/Fall: 0,-5. West/Winter: -5,0. The Sun is at 0,0 suffice it to say.
Let's also assume there is no substantial interstellar medium. That you are essentially seeing a matterless void, although naked space. I.E. There is distance and there is time and mass, but nothing between the sun and its planet at any time massive wise. Space is empty but for these two objects of mass.
Now at at the Summer Solstice, the planet is at a specific point on this 2d grid, correct? Yet clearly, it is not at all, despite the complete and utter absence of mass, invalidating all the other points it will go to. For instance: In 6 months, it will be exactly opposite of where it is now, in relation to the Sun it orbits. Clearly, it doesn't just "create" that space, yes?
So you have a real point, regardless of the fact that it has no matter, correct?
Sooo.....there is a difference between it and pure nothingness, no? And therefore, it makes sense to discuss a grid even in the absence of mass, where something can be placed in it.
Now if you remove the Planet and the Sun, and we have shown that it is okay to have no mass some place, then clearly it is okay to have no mass no place. We are thus left simply with a matterless, timeless (as there is no objects to make time needed to describe the situation), blank grid...But a grid which differs from empty space.