A couple times a year. Champagne, mimosa or bloody mary are all acceptable. I couldn't get used to a beer with breakfast although on vacation I seldom wait until noon.
A couple years ago, I spotted a sign at a Pensacola restaurant advertising "bottomless champagne". Imagine my disappointment when I discovered they were just referring to the glass. They paid for it in champagne, I tell you! I bet we sat there getting refilled every 15 minutes for 3 hours.