This is a very subjective answer, it depends a lot on each person's fitness level, whether they are riding a road bike or mountain bike, whether they have any mechanical issues, the weather, how often they stop along the way and for how long, etc.  Last year I finished before 1 pm but there were only three or four hundred across the line ahead of me I think.  I was able to get my gear, load my bike, get changed, have a bite to eat and be on the 2 pm bus out of there.  I was home in Coquitlam with my bike before 6 pm.  But a lot of things had to go well for that to happen and I felt I rushed a bit to leave instead of hanging out and enjoying the experience.  I would say leaving between 3 pm and 5 pm would be typical and then it is about 3 hours or so to get back, plus getting your bike if you aren't driving yourself back, etc.  Not sure if this helps or not.