No need for stocking up, that is just fear tactics from the fascists who do not believe in Democracy better known as Remoaners. Why there is a fear of a "No Deal Brexit"
I cannot understand, take a common sense view of a "No Deal Brexit" the EU do not want to lose one of it's biggest contributers and who also receive the least back, so common sense tells you of course the EU does not want us to leave, in which case what can they do to persuade us to stay ? Of course ! offer us the crappiest Exit Deal possible that ties us into the EU for as long as possible and cost us as much as possible.
So lets try Common Sense again, leave with a "No Deal", cost to us NOTHING ! But then there is the threats of huge duties of British Goods entering Europe and also purposely delaying British Goods entering Europe, that sounds really awful for our businesses. But wait a minute...... Europe export more to Britain than Britain exports to Europe, so we just need to threaten the same high duty and purposely delaying European Goods entering Britain. Do you really thing the European Motor Industry such as Mercedes, VW, Audi, Seat, Renault, Pergeot, Citroen, Fiat, Alpha Romeo and may other car manufacturers would put up with sales damaging high duties and delayed deliveries ? And what about the huge European Wines market where Britain is the biggest sales market, France, Spain, Romania, Bulgaria, Germany, Italy to name just a few of the European countries that would suffer, then there is the Holiday / Tourist Market do you think that Spain, France, Italy and almost all of the other EU countries will not want to lose the British market as it would be a big blow to them.
Negotiating terms after leaving is the only real common sense option and the only was that Britain will not be shafted.
Also remember there are 53 Commonwealth countries and 14 British Overseas Territories (That sounds better than the remaining 27 EU Countries) that will be more than please to trade with us without the EU duties that they had to face previously.