Since you left that out I could not check on a newer Android or an alternate Android from Samsung or XDA.
I know that details don't seem to matter at times but here it will. You can check to see what is at Samsung for an OS change, and if that's not going to happen, check XDA.
This will take a lot of work on your part.
My Galaxy Tablet runs on Android 4.4.4. It only has 8GB capacity and is full. My external SD Card is 35GB and has around 20GB empty.
I have tried to free up space by moving CoPilot to the SD Card, however I get a message that Android 4.4.4 does not allow the changing of files to enable this function.
Is there any means by which I can overcome this problem?