Very producer dependent as style and liqueur d’expedition choice play big factors, but a good rule of thumb is a minimum of 6 months though I’ve had wonderful stuff that was only aged a week post-disgorgement so there are no hard rules and only general guidance. You need time to marry the Champagne and the wine or wine+sweetener that is added after disgorgement. You also need to allow the wine to settle after the shock of oxygen and the often addition of sulfur (though Beaufort adds none). Most producers will wait at least 3-4 months before shipping something out with the goal of it hitting the shelves with at least 6 months of age. Personally, I would like to always wait at least a year, but it doesn’t always work out that way. Selling anything that was disgorged just a couple months ago is irresponsible in my view.