The warm period in Europe lasted from the 900’s to the 1300’s.
During that period vineyards existed as far north as Scandinavia. However, as what became the Little Ice Age began, it became increasingly difficult for vineyards to grow in England, Ireland, Germany, Poland, Russia and Austria and wine became difficult to find and expensive. When the Mishne Brura paskened to allow kiddush shabbos morning over non wine , he cited a difficulty getting wine. This was the reason.
