One of my holiday time student jobs was at a very smart wine merchants in London. It still sold Champagne in pint bottles - apparently this was very common in the earlier part of the 20th Century but, by the time I was there in the 70s, it was down to just Bollinger (IIRC) who bottled in this way.

The legend went that a husband and wife found a bottle too much for breakfast and a half bottle too little. A pint was perfect!