This thread has ignited my desire to try playing BG3 with a 6 person party, though somehow I never had that same desire with DOS2. It's probably knowing that it'd be overwhelming in DOS2 with its AP system allowing you to potentially get 3 actions per turn, compared to BG3's much more strict action economy in comparison.
I'd much rather wait until we get more companions, though. Nothing can convince me to include Astarion in my parties.