How do I manage huge multi-shoot video projects without drowning?

You can manage a project now, so the workflow is not the problem. The huge multi-shoot jobs bury you because the sheer volume outpaces any system built for smaller work. That is not a skill failure. It is the point where a good personal method has to become a real structure, and that transition trips almost everyone. Big projects are not managed by working harder. They are managed by a system strict enough that it does not depend on your memory. On a small job you can hold the shape in your head. On a huge one, if it is not written down, labeled, and organized the same way every time, it will bury you no matter how sharp you are. The structure carries what your head cannot. Before the next big one, build a naming and folder system on paper first, and follow it from the very first file, not once you are already drowning. The rule is set the structure before the volume arrives. You already know how to manage. Now let a system do the remembering so the size stops burying you.