I did that once. For a whole documentary, w/ no cue but the script. He'd heard my work before and trusted me w/ that one.
When I finally received the tape the day before the deadline, I was pretty much done. I only needed to finalize everything and mix it down - which still meant a lot of work. And much to my surprise, my musical cues fitted perfectly. At least I thought so.
Come the deadline, I sent the guy all the files (internet, late 90s connexion).
He liked one piece a lot and asked me if I could re-write rearrange all the rest (5 pieces IIRC) like that particular one he and his wife dug (obviously, that particular piece was the closest to a filler, imho).
Oh and he wanted that for the next day.
18 hours to re-write/re-arrange, mix down/master and upload via a 56k modem.
I never saw the final results, but he loved the material.
So it can be done. ;)