Look at a map of wine producing regions in Europe. Today wine production ends in west Germany and only really starts again in south-eastern Czech Republic - with some tiny local exceptions. In the middle ages, wine was grown in that gap too. And people start doing it again now.
Yes, there was a warm period where wine was grown as far east as what is now the Czech-German border. It was followed by the little ice age.
What does east have to do with that? FYI wine is still grown north of Prague, on Czech-Austrian border, in Slovakia, Hungary, Moldova, Georgia…
Look at a map of wine producing regions in Europe. Today wine production ends in west Germany and only really starts again in south-eastern Czech Republic - with some tiny local exceptions. In the middle ages, wine was grown in that gap too. And people start doing it again now.