There's a few guys that they're going to stay put at 18 and draft if they fall.
I think those men are Saquon Barkley, Derwin James, Joshua Jackson, Minkah Fitzpatrick, and a couple of highly-rated defensive linemen such as Arden Key.
Chubb's stock is rising, so he may be added to that list. I believe Chubb is going to be excellent. Sony Michel and Derrius Guice are two other prospects I would enjoy, but they're below Chubb.
I think the most likely scenario is that they trade back into the mid to late 20's, pick up a day 2 pick, and draft a defender and running back with the top 2 picks. I would love either (Fitzparick/Harrison) Alabama safety, either Georgia running back (Chubb/Michel), Guice from LSU, or edge to mitigate the loss of Avril with those two top picks.
After that, restock the defense and try to draft a tight end somewhere, and I'm good. I want the players drafted to have some serious chips on their shoulders. Attitude is needed.