I`ve winter sown several Verbascums with success and I don`t see why this one wouldn`t work for you. I`ve read a few sites and they say it`s good to zone 5 so maybe if you pace it in a micro-climate area in your gardens or mulch it well.

7``snowbanks` !!!! Ugh!

I can't remember if Rosetta was among any of the verbascum that i've WS in the past, but they all did well. Too well - i'm pulling them out by the dozen! :>