8 degrees Celsius = 46.4 degrees Fahrenheit...Sure!
10 years might be hitting the outer limits. 20 years...who knows?
One problem is the Cellophane(?) construction of the chemical/developer pods.
These developer pods don't seem to be totally air proof. At least...not the old Polaroid pods!
Over the long-term...the chemicals within the pods can dry out and/or harden.
Don't stack the boxes of pack film. Store the boxes standing on end, (like books in a bookshelf).
The Fuji instant pack film is great stuff, though. When Fuji instant film was allowed in North America
following Polaroid's re-organization bankruptcy in 2001(?), I thought that Fuji was a better product.
The last Polaroid pack film was produced at or before their liquidation bankruptcy in 2008(?).
That's going on 5 years now. Most images I see from those shooting old Polaroid film...today,
their images show a lot of color shift, and/or incomplete developer spread due to dried out pods.
Today, unless shooters of Polaroids bought their film new...five years ago,
they have no idea how the film has been stored. It's quite the 'crap shoot.'