I don't really think of musicals that have been "influnced by Sondheim" as having "Eleven O'Clock numbers". You get songs like "Being Alive" and "Rose's Turn" because the character has come to the point of catharsis in the story. Had "Marry Me a Little" or "Happily Ever After" remained in "Being Alive"'s place, would you have said that they were "Eleven O'Clock numbers"?
"I'm Going Back" from "Bells Are Ringing" is a classic example. Judy Holiday told the writers when the show was out of town that she wanted a big song at the end of the show, or she might not come in with it. So, Comden and Green took a look at their book and picked out one of Holiday's biggest laugh lines and build a song around it.
That's the type of old-fashioned thinking that gets us "Eleven O'Clock numbers".
The modern shows that have "real" ones are the old-fashioned shows like "Hairspray" ("You Can't Stop the Beat") and "Dirty Rotten Scoundrels" ("Dirty Rotten Number").
"A coherent existance after so many years of muddle" - Desiree' Armfelt, A Little Night Music
"Life keeps happening everyday, Say Yes" - 70, Girls, 70
"Life is what you do while you're waiting to die" - Zorba