Vignar-Gray Mane can sometimes be found sleeping in the Drunken Huntsman in the double bed (000A6E73) upstairs.
As far as I can tell this isn't supposed to happen since he's has a room in Jorrvaskr. Strangely though, the double bed and single bed in the upper portion of Jorrvaskr are marked as owned by VignarBrillFaction, which means they can be used by either Brill or Vignar. Based on the Reference Editor ID, the double (00075DAD) is meant for Vignar.
Since it has no ownership setting, maybe the double bed in the Drunken Huntsman was intended to be assigned to a specific NPC or faction. I've also seen Nazeem and Ahlam use it, which probably isn't intended either. Anoriath and Elrindir already have single beds specifically marked for their use.
Screenshot:
https://i.postimg.cc/GtXJvkrG/Screen-Shot201.png