Thanks to the ladies from my PatternMaster Users Group, I got a good idea on what to do for a cover-up. I drafted a bolero jacket with two-part sleeves. And by golly, I think we have a winner!
The sleeves need a little tweaking, but that's about it! The outer shell will be the red suede-like fabric, and it will be lined in the dress fabric. I will probably bind it all the way around with a narrow black bias binding, and will also have black cording along the top edge of the dress.
Due to previous obligations, I won't be spending any time in the sewing room until next Monday. The gala is next Saturday the 28th. I'll have just a few days to sew the final dress, the bolero, Bob's vest and tie, and re-cover my clutch purse and possibly a pair of shoes. And pick out jewelry: I need to check my jewelry box for nature-themed stuff. Not sure what I've got in there!
Thanks to everyone for your comments and suggestions. I really do appreciate the input!