I have some examples.
(Ted invited Robin as a date to a wedding.)
How fancy are we talking about here? Probably referring to style or proper attire as a guest to the wedding.
How fancy do you drink your wine? "Fancy" would be an unusual word in this question and I would not know what the speaker meant.
How fancy should clothes be for Thanksgiving? Same as for the wedding question, but for the holiday, Thanksgiving.
Does this mean "how much do you like"?
Student or Learner