Don't worry

I worked for Sherwin Williams Paint co. for 6 years we had entire pallets freeze and we never had any complaints from a single customer. Just Set the Latex Gallon in a nice warm place in you home for about a week . Then stir it extra well and it should be good as new just make sure it is all thawed, if its not put in back in the warm spot for a couple more days.

Once the whole gallon is thawed paint your heart out it will work just fine interior or exterior.

Thanks

Thank you, that was exactly what I needed to know.  

Antifreeze

Paint manufacturers add antifreeze to paint for just this reason, they don't know what might happen when shipping. However, they do indicate that multiple freeze/thaw cycles would not be good for the paint. I believe that Goldon Artist paints says that they test for 5 freeze/thaw cycles with their paints.