I usually leave mine to defrost at room temperature for about 24 hours. As a general rule I never take 120 film out of the foil packet until I'm ready to use it, whether its been frozen or not. On the odd occasion that I have taken it out of the packet, I wrap it in kitchen foil just to be on the safe side to avoid the possibilities of any light leaks. I also regularly refreeze film, if I've not used it and conditions change and have never noticed and difference. Don't forget, it's also probably already been frozen anyway before you get it by the manufacturer or seller to manage stock levels etc.