I do think that for a special occasion, such as a dinner party as in the OP, most people make an effort with their appearance.
The dress that looked gorgeous in the mirror at home with appropriate shoes might not look so good in stockinged feet!
Prior warning would allow guests to adjust their attire accordingly and/or take alternative footwear - I think you can get mules with a small heel, can't you? 
Professor Jason Arday - plagiarism etc
If Vegetables Get Smaller and More Expensive....




