Just heard yesterday that Windows 10 S is limited, to third party manufacturers, to celeron processors and 64gb eMMC memory. Given that we were at the 11th hour of placing an order on a spec of the pentium N4200 with a 256gb SSD it was very disappointing to be told of that limitation. How the low spec device would perform in a classroom as a multi user device is anybody's guess.
We'll go back to Windows 10 education for this particular project but has the 10 S specification ceiling been announced anywhere? I can't find anything, anywhere.
In terms of storage space when using our Set Up School PCs app devices can be optimized for shared usage, including better management of user profiles. Try using the shared device setting - 64 gb should work great in these scenarios. You can find more information on Set Up School PCs here: https://docs.microsoft.com/en-us/education/windows/set-up-windows-10.