Asus Zenpad 8 S Android 5 vs Android 6

[AC Question]

My son broke his Asus Zenpad 8 S running Android 5 OS. (Majorly cracked the screen.)

I just replaced it with a new Asus Zenpad 8 S...running Android 6.

Android 5 could be rooted, and I could move ONE app from one device to another.

Android 6 can't be rooted at this time (or, at least, I don't have the technical know-how to do so). (ONE APP! GAAH!!)

Is there any way to move the data from this ONE app from Android 5 to Android 6?

If I can update the old Zenpad to Android 6, does it actually save ALL of the appdata so I an move this game to the new tablet?

I am about to pull my hair out here...

Thanks!