Can I Store My Organic Soil In Garage During Cold Months?

I have bags upon bags of Sunshine Pro potting soil organic. I have both a space and a gnat issue. The gnat issue seems to be small as I just see a few small gnats flying around or near my bags of soil which are all now stored in closets with tarp around them, the space issue is more severe. I want to put all of the Sunshine bags in the garage where it will get as cold as 0 some nights.

Question one is will this hurt my soil in any way?

Question two will the cold kill any possible gnats or eggs living in my bagged soil?

Thanks.

the colder the better, the organic matter won't decompse as fast.

No and No.

The cold won't hurt the soil mix and neither will it kill the eggs.

Wet