Each full save is ~15 MB. Even 100 saves are only 1.5 GB — trivial on modern systems.
If you can provide more details about "Nightmare Hunter" (such as: nightmare hunter full save better
Once you've loaded a complete save, prioritize checking out these highlights: Hidden Boss Fights Each full save is ~15 MB
: Access to all maps and secret boss encounters. How to Install a Full Save nightmare hunter full save better