I know canon is now with Disney but they still draw a lot from the books. And in the books it is suggested that the Emperor was much stronger in the Force than any of us realize. There were many books that suggested he actually controlled much of the activity in the Empire thru the Force by directly controlling individuals. Even so far as to control his military during combat with the rebels. It would be very fanciful to suggest that in the Disney-verse, but in the books it was very sinister and completely believable.