Last I remember, haven't modded this game in years, height was in a single byte. That only allows 256 spaces. The game is still 256 levels from absolute bottom to top.
Lets have fun and up that to a DWORD. That would give us 4,294,967,295 levels from bottom to top. In scale, that wouldn't even get us into orbit. A QWORD might get orbit, but not to the moon. The closest planet would be further than any number native to a computer. In this voxel scale.
You could warp to another planet. Forget the distance between. Then it's just another Navezgane.