Here's another riff on it though, just to the question about 'what if they want temp NPC hangers-on for story purposes?' and doesn't going from 6 to 8 make the party then too unwieldy? My thought on this is that it really shouldn't, at least not if it was done well. What made Baldur's Gate unique and entertaining at the time, was really the god mode aspect of controlling multiple characters at once. Even in addition to the 6 standard PCs, you add on to that the idea of familiars or sidekicks, plus the various Koraxes and such, plus standard summons, and the game really needs to work with a party of at least a dozen, not just 6. ​I mean that's how it was in BG2.

In BG1 there was no limit to the amount of summons, other than the number of spells you had memorized, and how far you wanted to push your computer's ram lol. You could storm Nashkell with a couple dozen wolves and a gang of bears, if you wanted to, and your character had enough spellslots. That was wild, and a blast towards the endgame there. But the BG2 limit seemed pretty sensible. It still left room for plenty of companion characters to each have their own buddy minion. Or to fill out the extra slots with summons if you went with a smaller party. Even soloing still usually meant making use of summons, whether through spellslots or special items or consumables like scrolls and wands.

I just think they should aim higher. The kinks will be less pronounced I think if they go big with it, and the possible party combinations will be much greater (even if we only end up with a dozen possible companions to choose from) as mentioned earlier. So I just don't see how they can go wrong setting up support for 6 sooner rather than later. Gives us something fun to test, and would many happy, or at least it would make me happier lol