By convention time the picture will be much clearer as to how many delegates Trump might lack or exceed for 1237 on the first ballot.
It is likely that many, if not most, of the uncommitted (said to be around 200 by convention time) will want to vote for a winner, not another also-ran who is mathematically eliminated.
I forgot about NJ. Trump gets to 1270 without a single delegate from IN, MT, SD, or NE.