@tim when I was on pen cartridges & renting a place with an really, really over enthusiastic fridge I quite often froze novorapid to the back of the fridge through the cardboard & plastic packaging.
Only the end vial closest to the element would freeze & even then not fully because of the mass of insulin & the heat transfer propertys. That cartridge would seem less effective & I’d need a few extra units, played havoc with the lantus though.
Kept our insulin in many a minibar over the years w/o any problems & if you think about it miniatures aren’t that different in volume to insulin… The bigger problem is getting back to find your insulins been replaced by a bottle of bells ‘scotch’ 