Wineries with operations in France and the US. For example, taste Joseph Drouhin Burgundies against Domaine Drouhin Pinots and/or Chardonnays from Oregon. Or Champagnes from Moet & Chandon or Roederer vs. their California counterparts.
Although a bit late, I could suggest wines of ancient Greece as in varieties dating back to classical Greece of Socrates and Aristotle combined with snacks/treats referring to that era, matching music (eg harp) and historical references.
One of my favorite themes is always “wines that don’t suck”.
What if you taste “wines that don´t suck” … and they suck?
Game Over man…
Of course I love the Riesling idea. However I would suggest to keep it focused on dry and maybe a Feinherb.
Then you find out who brought the bottle(s) that suck and don’t invite them again.