Before the Roman empire brought alcohol to areas of Northern Europe around two thousand years ago, do we know if the native people of Britain and Scandinavia drank alcohol?
My preliminary search is showing up Nada.
Yes.
Residue analysis has found chemical signatures consistent with the presence of honey, and organic compounds associated with fermentation suggesting that mead was being drunk by the late Neolithic / early Bronze Age "Beaker peoples" in Britain and northern Europe.
If you want more details of the processes involved, and the nature of the evidence, and if you have access to back issues of Antiquity at a local library (or deep pockets), there's an article on Bronze Age mead in Volume 52, Issue 205 (July 1978 , pp108-113).
For more information about how we know the alcohol was being made deliberately, and not just the result of natural fermentation processes, you might want to read check my answer to this question.
Mead was the alcoholic drink of northern Europe, particularly "Celtic" northern Europe, e.g. the British Isles and northern France. It also figures prominently in the literature of the Scandinavians. This drink was made from honey rather than grapes, unlike Roman wine.
Recent archaeological research suggests that "beakers" for producing mead (or its alcoholic predecessors), could go back as far as 4000 BC, that is, to the Bronze Age.
Romans brought wine. Before that the people of Northern Europe drank some kind of beer. Even in the Roman times the imported wine was expensive.