On the basis that Mykolenko has already replaced Digne, I reckon we will bring in another two this window, so it wont be an immediate big churn, a right back and a centre midfielder squad player is what has been suggested. 
So next summer,  reckon this is what will happen (unless DCL/Richarlison is sold sooner)
Keepers- as is.
Defenders- 
Coleman, Mykolenko, Nkounkou, Godfrey, Keane, Branthwaite + new right back in Jan.  
Out- Holgate and Mina, In- new centre half. 
Midfield-
Allan, Doucoure, +1 new player in Jan + Gomes/Davies 
Out- Sigurdsson, Gomes, Gbamin, Delph, Davies.
Forwards-
Gray, Gordon, Townsend, Iwobi, Rondon.
Out- Iwobi, DCL and Richarlison, In- three attacking players
I suspect Calvert Lewin and Richarlison will both be sold in either January or the summer unfortunately, giving us a complete reset financially and giving Benitez a massive budget to bring in the players he wants... but I dont see more than 3-4 players per window to be honest.