Impact of Freeze-Thaw Cycling on....Basically, even after being fully frozen and thawed several times-- for hours-- the EPINEPHRINE solution from an epipen was just fine-- no change or degradation.
That says nothing about possible damage to the device itself, however-- and that could very well occur upon freezing, since the solution containing the epinephrine might well expand and crack the glass, or burst a seal.
Still, this should be VERY reassuring in terms of temperature excursions at something well above actually freezing (which probably doesn't occur above about 30F or -1C).