Since there are periodically summoned enemies that give XP, so you can reach whatever level you like, although my guess is that there is a hard limit (way above what people will normally reach after finishing the game).
Without doing that there is enough XP to reach level 20-21 if you are not skipping quests, 22-23 if you solve quests optimally (get the charisma xp and the combat xp) and possibly 24 if you kill absolutely everything in addition to that.
Last edited by eidolon; 02/08/14 08:38 AM.
