Hmm interesting video. At 1:11:15 tokshen actually asks directly if it will be possible to create the full party as a single player, and the Larian employee actually can't answer if that will be in the game, so that sort of backtracks somewhat from Swen's answer in the Reddit AMA. To be fair this interview is probably done before the AMA, so maybe they decided on it in between. Would be really nice with a complete description of all the different single player options though.