My stash of bodywork supplies including a few pints of touchup paint (basecoat) and a gallon of clear were exposed to freezing temperatures for about a month.

Does the cold weather affect the paint etc., or is it OK to use once reduced & hardened properly?

Thanks in advance!

Reducer is not affected
Paint can be if it gets cold enough, but I think the Hardener is the first to go. Hardener also has a limited shelf life.

I was told it isn't a problem as long as the temp isn't fluctuating up and down everyday.

Chances are many items have frozen in transport.

Let the products warm up slowly over time and shake the paint well.

Anything in a spray can may be dead however due to propellant leaking.