I am aware that one or two of the English vineyards do sell small quantities of pressed grape juice. The one I have seen is only available occasionally and is a white wine variety. Most of the wine produced in England is white although one or two vineyards make a red. I don't know what they are like.
However I have tried reds from the Loire valley on my tours in France but to be honest they are what I would call " slurping" or "gulping" wines and lack the robustness, flavour, bouquet and body of wines produced further south.
When I visit France ( I have friends living in the Dordogne area) I inevitably bring back completed wine rather than grape juice. I use "Cubitineres" of 20 litre capacity and treat the wine with sulphite to permit the usual 4 day journey back toward home.
However this year my trip to Europe was my pilgrimage from home to Santiago de Compostella in northern Spain -- all the way ( 2340.4 km) by bicycle -- and camping all the way -- 7 weeks in all, in April and May. I actually cycled round the edge of Bordeaux and also through the heart of Rioja in Spain but my bike was already loaded to the limit and I couldn't manage even case of wine ( my 2 litre collapsible water bottle in my rear pannier was however filled with the local wine of the area as I travelled )