That level of decrease will affect operations and cost efficiencies, but not put the brand out of business on its own. Production can be reduced, locations can shut down and lay off employees, but not stop the business entirely. Closing down the brand will require a conscious decision on the makers' part.
One of the things keeping Bud Light going is the deep refund offered right now.
I know a couple of guys buying it up and getting 24 pack cases for basically FREE. They are getting refunds by using family and others for the refunds.