The dress looks very promising (especially since it seems to be a ponte knit fabric), Traci, and I hope that the 12P will be processed too so that you can compare sizes.
For dressing down, I like your idea with the boyfriend cardigan and loafers. Maxi cardigan and short booties, like Viv suggested will look fab too. Or maxi cardigan + sneakers, oxfords or casual flat knee-high boots.
And as Nancy mentioned, definitely with a denim jacket.
A few more ideas:
- Add a leather jacket + a fun bootie
- Fun kimono as a topper
- Layer it over a lightweight long-sleeved turtleneck top (like the ones below)
- Wear it with a poncho sweater or flowy batwing sleeve top (like pictures below) so that only the bottom part of the dress is showing and it can function as a skirt.