Kind of a Steady State model there. As to empty space, if you can measure it that would mean you are putting something in it to measure with so it isn't empty anymore. The ice sphere might be an old style black hole so it wouldn't radiate anything and there could be truly empty space outside although by saying outside we are putting a determination on the empty space and for that very action it isn't empty anymore.
The distance between objects would be measured. The span would contain other objects, larger and smaller, as well as other energy forms. When new matter erupts, it pushes everything around it outwardly, generating or creating its own nest, as only one unit of matter can reside at an address. An expansion of the universe, but with no consequences or phenomenon such as compression, for the inner ceiling of the ice would be melting to make room for the new matter wihout robbing any other unit of matter of its allocated volume of space.
"The ice sphere might be an old style black hole so it wouldn't radiate anything and there could be truly empty space outside although by saying outside we are putting a determination on the empty space and for that very action it isn't empty anymore
In my model, there is no 'outside of the ice sphere. It goes on forever and melts as needed inside the sphere.