In my opinion, the only possible way to take DeGea is to sell Szczesny.
You can't put 2 (expensive) roosters in the same house.
This may later be done by the Juventus. You're right, there's no way De Gea and Szczesny will be in the same place. I did not realize that the De Gea 4 - 5 year Contract reached 100 million.
If Juventus still want to get de gea, they inevitably have to sell Szczesny.