Even if you aren't on a dedicated sleeper service but flying CW that evening you can access the pre flight dining.
I've done that in ORD and JFK, you can then have a full service again on the flight or just try and go to sleep.
Although if in F lounge you then have to go across to the dinning area, although when flying from ORD and using the F lounge they didn't mention the pre flight dinning. option