I would suspect they will come in short of 20 million, but even if they sign cooper to 20 million it would still put them in at about 13-15 million this season in cap, which leaves them with 63 million for other players in 2020. They are going to restructure or cut Crawford (will save up to 9.1 Million), with a restructure putting their cap at around 67.5 million after Cooper signs. If they need to, they can restructure Zack Martin to gain around 8 million and Lawrence to gain 12 million. That would push them up to 87.5 million after resigning Cooper to a new deal. They could restructure some others, but those two are the best candidates to finish out their deals.
It is absolutely doable from a financial perspective.