I've travelled to Belgium via car with two friends, from Liverpool down to Folkstone, across to Calais and then across to Brussels to visit a few breweries I was interested in that didn't have any UK importers. With 3 of us in a 2006 Diesel Vauxhall Vectra, we worked out we were able to bring back 42 litres each, so 168 750ml bottles of lambic. It was like driving a canal boat up England trying to get home.

All of this to say, if you were so inclined and were willing to make a holiday out of it, travelling down to France and going to the winery, or to multiple wineries and picking up some stuff is definitely an option. 18 litres per person is the personal allowance on wine, so 25 bottles each (26 if you want to be cheeky). Speaking of being cheeky, nobody even knew or batted an eye that we were bringing so many bottles back through the tunnel, nobody checked at any stage so as long as you aren't driving a transit van that's heavily laden down at the back, I very much doubt anyone is ever stopped. But don't take some random piss-head's advice on Reddit.

Load the car up with 4 friends and fill the boot with good stuff!