In iOS 11, Apple introduced a feature to "offload" apps to reduce storage usage on the device. In the Storage preferences, there is a list of apps, sorted by storage usage. Offloading an app will remove the app itself but keep user data, so that nothing is lost when the app is reinstalled.
The problem is that while an app and the associated data might take up something like 1GB of storage, which will make the app appear at the top of the list, offloading the app might only reduce storage usage by a small amount. The app is removed from the lost nonetheless.
This now results in the problem that a lot of storage might still be used by the app data (which is visible in the storage map of the iOS device as "Other"), but it is not possible anymore to find out which app uses the most data. This is important though because only fully deleting the app will also free up the app data storage.
Does anyone have an idea how I can find out which of the offloaded apps uses the most user data?
I am on iOS 11.4, and can sync with iTunes on Windows (no Mac).
My original "use case": I was recently forced to migrate from a 64GB iPhone SE to a 16GB iPhone 6s. Thanks to iCloud backup, I have all of my apps still available on the phone, but I had to offload quite a few rarely used apps. Now I have about 6 GB of "Other" storage, which I expect is at least partly the user data from the offloaded apps, and the iPhone is constantly out of memory. My problem is now that I really can't tell anymore which of the offloaded apps uses the most user data, because they are not shown in the storage overview.