Those are some mighty looking woody peonies, LG! I'll bet you were pleased. How awesome that you got a freebie bonus plant; I haven't noticed too much of that these days.
Hi Anya! Schulze does have Impossible Dream, and based on the gallery image it appears to be the correct plant. Have a look here.
https://pfingstrosengaertnerei...
I am not sure how easy it will be to order and it may require an enticing group order for them to consider it. I had some help from a friend so I really don't know what happened behind the scenes and I dare not look a gift horse in the mouth!
I plan on dividing Impossible Dream one day, but that day has been delayed with a recent revelation from Don Smith that this plant is possibly diploid. If true, this will radically produce my pollination approach and there could be a good chance of producing viable seed and intersectional hybrids from Impossible Dream when hit with the right pollen. Ironically Don does not have this plant himself to confirm. That's enough of a tangent for now, but I think I need about two more years before division and if you don't have the plant by that time, you'll be the first person I let know when it's under the knife!