My cousin, who lives in Chicago, emailed me in a panic. She has a dozen or so nice Irises that she had not gotten around to planting -- and the Chicago weather has probably turned for the winter, not leaving enough time for the rhizomes to settle in if planted. She asked what to do. Her garage is not attached to the house -- so it likely gets as cold as the air outdoors -- would likely freeze rhizomes. Her basement is finished -- and therefore heated to whatever temperature the house is. Probably too warm for rhizomes.
So any suggestions? She also planted a half dozen or so a week ago -- and even though they're in the ground, are probably in the same position as the unplanted ones.