Here's what I would guess for DA:I so far:
Varric: loyal, helpful, friendly, charming -- Hufflepuff
Sera: very for the 'underdogs' (friends of red jenny), probably outspoken, humorous -- either Hufflepuff or Griffyindor, but since she seems more focused on helping people directly instead of the greater good, I'd say Hufflepuff
Iron Bull: He's hedonistic that's for sure, but I don't think he's particularly cunning or willing to hurt others for his own gain, so I say -- Gryffindor
Dorian: -- Ravenclaw or Slytherin... his necromancy and background gives me Slytherin vibes, though
Cullen: Leader type, takes action quickly -- Gryffindor
Cassandra: same as above -- Gryffindor
Solas: Introverted, mysterious, very clever in his area of expertise -- Ravenclaw
Josephine: She seems diplomatic and sweet -- Hufflepuff
Cole: His main priority seems to be to help those who need it -- Hufflepuff
Blackwall: Grey Warden, protector and seasoned fighter -- Gryffindor
Vivienne -- ambitious, manipulative, has her own goals and motives -- Slytherin