As you can see, this brings the memory footprint from 11 GB to 2.0 GB, and that's before doing any further operations in Grasshopper. Of course, if you need to operate on all of the geometry, this may not be the right approach. However, if you only needed, for example 10% of the objects, you could use Ghost Geometry to filter down to the items you need, then Manifest that 10%, and keep your total memory overhead to a minimum.