Actually, it was answered by BubbaBlitz…
If you create the cache while zoomed out, you can cover a really large area with very little space requirement. As you zoom in and get to the higher LOD in the cache map screen, it will increase in size. There are 3 levels of cache detail. WHen you’re on the highest level, your cache even for a small-ish area could potentially be 10s of gigabytes.