I found that when I do all-nighters (although it's been a while since I've done one), I get a "second wind" of sorts from mid morning until late afternoon. So if I want to make sure I don't go to bed too early, it's only really the last two hours that are hard, although they can be very hard (especially since you don't want to drink caffeine or anything like that since that would affect the sleep quality).

Fresh air and light exercise help me during those last hours, but it can be mentally difficult to force myself to doing that.

Again, it's been a while since I've done it, so it may have been a symptom of being a bit younger. Maybe I wouldn't be able for it now...