Maybe it's very different from the other souls games, but as I remember it is you die, you go back to the last bonfire, everything resets, except the stuff that you left lying around. Cache the pristine start area as 1 chunk and apply the change log you have already.
you have to load that state from hdd when you die, regardless, because that state cannot sit in memory for the exact same reasons the game dumps obsolete data from memory when not in use and streams in new data as you progress.
the configuration isnt the issue, parsing the required data for the area is.
dumping a state to memory is not a fix, its an illogical waste, as you progress the state becomes obsolete, frequently updating the state in memory requires a variable pool, wasting a chunk of memory that the game needs for streaming its assets as you progress.
Let me put it bluntly.
Instanced states is not possible on consoles, there is not enough memory, and saving state to hard drive would decrease load times SLIGHTLY for disk based games, but INCREASE load times for digital download versions.
As someone with extensive experience working with memory management for shaders and texture data, as well as model lod, uvw streaming and as an ex employee of From software, I will simply leave it at this, your view of memory management does not work for the XBO or PS4.