Like Julie I had a few plants follow me home from the Lilyhemmer meeting, they were planted yesterday. I'm zone 4 and would not advise someone else planting this late here.
Early in my hybridizing I divided and lined out some selected seedlings the day before Thanksgiving, didn't think anything of it...but after someone scared me by saying "you did WHAT?" making me worry all winter I never did that again. All the divisions survived and bloomed fine the next year.