So here finally the picture of the dress.
It fits nicely at the bust, and also falls nicely from the hip down. The part inbetween is not so good because of the size difference between my bust and hip. I took several cm in at the side seams and darts, but now there is some volume in the front where my body doesn't have much volume. But even if I had found a better way to get rid of the eccess fabric, I realized that this type of silhouette is not good for me, just emphasises the pear. I wore (and always should wear) the dress with a jacket over it, to give me more "weight" on top.
The professors had some tough questions for my husband, but I did my best to have a confident expression. The party was nice, and now he works in New Zealand for two months.