Sorry, I haven't been back to chat due to work and holiday preps/shopping etc! If anyone needs to reach me, I am not very good about checking in often...feel free to message me :D
Wintersowing poppies: I WS mine Jan and feb anytime, they wont sprout til april or so (Mass. Z6) when they are ready, but you dont have to worry about the taproot when seedlings. It's recommended to transpant your poppy seedlings early. I did so first year with some peony poppy mix, they were 3-4" and they transplanted fine. But they do develop a longer tap root and if transplanted late, might not like it much, which would also affect their survival.
Some perennials (not poppies - Ive had them sprout with 2 weeks of cold) require a longer (4-6 week) cold stratification process, that's why you WS in Jan/Feb.
HAPPY HOLIDAYS ALL!