Well,after curing for several hours the top layer of plastic came off beautifully . I have a dedicated freezer for this stuff plus I put it inside a plastic bag!
The reason I wanted to try this was so I could do some carbon lay ups. I also have found carbon hard to wet out in place so this method as you say will be much better .
As for how long it will last? I will try to make a test every week or so to see if there is significant degradation of the pre preg.
I will report with the good or bad!