As the OP is a new member, it may be their first visit to DL. They are looking for something longer than a five day, so I will go out on a limb and guess that they are looking to spend as much time as possible in the parks.
If I had been to the parks more than 10 times, I could see that spending more than 4 or 5 days in the parks, would probably be more than enough. What I take issue with is, when a new member is looking for suggestions on spending as much time as possible in the park and people chime in with 3 or 4 days is enough.....and it happens every time someone new asks "how many days".
Yes I live in Alberta. However, flying from Canada and Europe to LA can be comparable. The park would be FULL of Canadians all the time if we ever got seat sales like you do in the U.S.