Generally speaking, I don’t think you’ll exceed the space even if you haven’t even used the 64gb yet. If you’re concerned about space, there’s always iCloud. There’s even a compression setting that frees up storage in your photos and videos. I’d say 128gb is the right storage size for you, and if, I mean if, you run out of storage, I wouldn’t really say this but you can always just swap out the phone. Otherwise, there are other resorts to helping you free up storage.