Hi oldcrow - I'm in
zone 6 here, and am also not sure how hardy they are. One year I lost 4 out of 7 bushes, and never really found out why, but I think that was the year I cut them shorter... I also love the spicey scent of the purple ones - my pink don't smell as much, but do make me sneeze!
I haven't grown any of the other
flowers you mentioned, though when I lived in Alaska the lupin were absolutely gorgeous! Some of my
flowers that had hoards of bees on them this year were the mini zinnias, sedum autumn joy, salvias, and purple hyacinth beans. My husband and I have never seen such ENORMOUS bees as this year - and tons of them!
If you are really concerned about the BB, you could always wrap it up in burlap so the limbs don't break off and it would help insulate it a bit.