SN in below freezing temperatures

[CanIStopTryingNow]

I'm getting 2 separate packages of SN incase one gets found. If I keep 1 in my car, probably by the donut spare tire, would it be ok in below freezing temperatures?

 

[Darkover]

The ideal temperature range for storage is between 15°C (59°F) and 25°C (77°F). It's important to keep it in an airtight container to prevent moisture from absorbing

 

[CanIStopTryingNow]

I guess I will only move the second one to my car when I use the first to attempt. If I fail, I don't want it to be easily found; I want to be able to make a second attempt once I get out of the psych ward.