I think this can work, I think I have set this up before, but I am not sure. You will need to use MediaCache:
When you install, take a look at the /conf/MediaCache.xml file and the documentation regarding S3.
Normally MediaCache is setup using an application with StreamType "default", but you will use StreamType "live" is the only difference in the MediaCache setup.
The schedule smil stays in the local content folder. Its playlist items will change from this:
To something like this:
<video src="mp4:bigbuckbunny_450.mp4" start="0" length="-1"/>
The abr .smil should be moved to the S3 bucket. The playback URL will be something like this (for iOS):
<video src="mp4:amazons3/[your-bucket]/bigbuckbunny_450.mp4" start="0" length="-1"/>