illinois is fine for growing it, might want to wait till spring though. I was suprised to find out Opium can grow in temperatures as low as 30 degrees. You will find it is suprisingly easy to grow although certain factors will determine how potent the Opium is. Google that.
they ones in the grocery store will work but some brands do somthing to the seeds to the germ rate is like 10% but thats ok because you usally have thousands of them
I figured they should be fine in lower temperatures, because after all- Rememberance Day is in November. Cold fucking weather in November. I'd love to grow some opium poppies but I think you'd have to grow an assload to get anything worthwhile out of it. Not sure though. I think I remember something about them being planted in the fall or winter too, so maybe you should check it up before you have to wait another year