Reticulated irises are rather opportunistic bloomers, so can and will bloom very early if given a chance. In my garden here in southern Sweden they will normally bloom in February-April depending on weather and cultivar, as some cultivars are much earlier than others.
What you describe sounds pretty normal to me
, especially as you have been keeping the pot in a protected spot in your enclosed porch. I wouldn't worry too much about it.
They are tough plants that can handle rather serious freezes even in full bloom, although everything has its limits. I would just make sure that the soil in the pots don't freeze to quickly if it gets cold. If you haven't done so already, adding a bit insulation around them can be a good thing. I always place my pots with spring bulbs in the ground in the unheated greenhouse.
