The potential is there for something similar, Katla may have erupted similarly in the 10th century, hardly likely for anything now to be as devastating though, those are very rare events thankfully. Then again, these things have to happen sometime. Anyway, this has moved away from winter prospects, I merely mentioned it as another variable.
There is also a study which points to evidence that the July heatwave in Europe resulted from a short term greenhouse warming created by the emissions from Laki and high levels of sulphur dioxide in the lower troposphere. This becoming less of an effect the further away from the volcano you went. Too far away to be certain of any evidence either way though I suppose.