ok.
A fresh start might be better, in fact.
Especially if in this final patch Astarion can bite that guy who is chasing him. Some decent dialogue for the next rest could be:
[Astarion] - Player, I need to take care of something, I will be out for a while tonight. Don´t worry, I wll be back in the morning.
[you] - ok Astarion, but please be careful who you bite.. no Tieflings, Githyankis, Ogres.
[Astarion] - Oh, don´t worry. I just need to teach someone a lesson.
[you] - [insight succeeded] - be careful..he got a wooden stake somewhere in his backpack.
[Astarion] - and I got a Fog Cloud/sleep/Darkness Scroll in me.
Ok...seriously though, my suggestions would be to:
(1) allow at least 2 built characters on the same story, BUT
(2) explicitly mention that extra XP will be given to the whole party if certain companions participate in specific quests;
such as:
Wyll fighting some goblins
Laezel meeting Githyankis
Astarion fighting the Hag
Shadowheart fighting the Absolute fake deity
This way, the player can travel with his 2 own characters, but will also mix the party according to the story
