Playing multi or solo by yourself doesn't cut out that many quests. Each NPC has only small quests to individually complete. (With the exception of two, I believe). Other than that, you can still do the majority of the game and quests. After you've beat the game multiple times, you get tired of the same bickering. Adjust the party and you still get more bickering and the same comments.
I've beat the game with NPC's and
extremely easily with a multi party of my own. I'm soloing now for the challenge. Maybe I'll try running through with a multi party of my own, but not allow any stats above 15.