We are above freezing now and the coat of ice has melted off the plants. It is cloudy, drippy and cold so I am not going out too much. I do not think my irises will be harmed by being frozen but I do think the blooms on taller stalks will abort. I have had it happen before where a bud will form and the stalk will grow then we get a really good freeze. From that point the bud does not get any bigger or attempt to open. when I feel of the bud it feels hollow and almost empty. The buds on the shorter stalks, the ones where the bloom stalk has not yet emerged from the fan, will have a better chance, although they may suffer some bloom damage.
Just have to be patient and hope for the best. We have several more nights of freezing temps before a brief warm up.
I did pull this pot indoors yesterday. It is IB Jangles and has six, some rather tall, bloom stalks in one pot. It is not a favorite but I could not leave it to the weather when it is making such a valiant effort to make a pot-clump.
In the spring, in the south, frogs and small snakes will overwinter in pots so if anyone is bringing pots into an area where it is warm make sure you check to see if there are any unwanted critters in them.