There was a comment on QI (BBC2) that in some areas medieval French rural peasants would almost 'hibernate' like bears to conserve energy. There was a teacher interviewed on Radio 4 last week about the effects of having a power station built in the area (one of the Southern English coasts, I think) recalling that new people moved into the village to work in it, including Scots, and that when their children came to do P.E. in winter, it turned out they had been sewn into their underclothes in the medieval way!

St Petersburg had tenement blocks which were very overcrowded (presuming Dostoevsky's painting a true picture) so I could imagine men might hang around on streets or in pubs, keeping the cold out with vodka, and there'd have been more artificial lighting by that time, I suppose.