Not too many late flights from CLE.
Using the top 100 US airports listed
here, ITA is giving me the following 50 operations (22 departures, 28 arrivals) Sunday night between 8 and 10 at night. Looking at 9 to 10, it's only 15.
And these are only from 100 US airports, so there may be more (especially international flights). I'm not aware of a place where I could see all of those.
From the link Dan posted
here, based on my research there are at least two spots which should be good for what we have in mind.