Generally, the 40 point mark is only for the Premier League, in the EFL it's usually 50, though there have been exceptions as already posted. I think it was Peterborough who went down with 52 and Walsall a few seasons before that went down with more than 50.
I can't see us rapidly dropping between now and May, we should be aiming for the top ten now, which would be just rewards for the turnaround we've seen under Rosie.
Whether we can keep him over the Summer, well. That's an entirely different conversation.
I can't see Rosie leaving us tbh, he has aims and a long term project with us...... Well Not unless a PREM team came in and that's just not going to happen unless he's successful with us and in that case he'll be in the prem anyway