Resizing all wsp based on conf files

After using graphite for a while we want to make extensive changes to the storage-schemas.conf and storage-aggregation.conf. Now this is fine for any files created hereafter. But is there an easy way to 'migrate' or resize all the existing wsp files based on the updated retention periods/aggregation methods etc ?
I am aware of the whisper-resize.py command, but you need to feed in the retention period for each file. Is there a higher level script which looks at the storage-*.conf files and resizes the whisper files as needed ? This would make migration super simple.
Any pointers if I were to write this on my own ?