Aloe Vera and Surviving Overwatering and Frost

I put my Aloe Vera plants outside as much as possible. They spent last Summer outside and even though it was the wettest on record and their pots were often swimming in water they didn't seem to harm.

Recently we had our first frosts so I took them inside however I forgot one large plant outside. Unexpectedly this plant survived a week of frosts and is actually doing rather well. So how cold a frosts is required to kill an Aloe Vera plant?

So Aloe Vera are even hardier than I thought. What is your experience?

N.B. From a book
Overwatering what should we look for?

A plant suffering from overwatering may appear to actually need water. The leaves or stems will wilt and turn yellow, sometimes dropping off. Someone seeing this might believe that the plant needs water and add to the problem. But once again, feeling the soil is the best way to avoid this.

When in doubt: Soil + dry = water. Soil + wet = don't water.