I think it's quite rare that an actress wins a prestigious award for a movie in which she has extensive nude scenes, including public ones. This is exactly what happened to Sara Forestier who won the César Award for her role in The Names of Love. Of course, it happened in France where they don't take nudity very seriously, but imagine this in the US. :)
P.S. Very curious people can find the naughty scenes here. NSFW.