There is no evidence that the Romans had any vineyards in the north of England. There are records of them bringing wine to Britain, but not of them growing it. The earliest real evidence of vineyards in England is in the Domesday Book, though even there it only mentions grapes being grown south of about Cambridge.
Even if wine has been grown in England, that doesn't mean that we were experiencing Mediterranean climes at the time. Bear in mind that, as a Christian country, we *had* to have access to wine, even if it was awful, and that for substantial periods of our history we have had a hostile relationship with France. There was once a cartoon in Punch magazine about how in order to make someone drink English wine it was necessary to tie them down first. There hasn't been a time in recent centuries where there have been absolutely no vineyards in England, despite the fact that for much of that time it has been a lot colder than it is today.