I guess they could also have it partially open when they have to - then open other areas up during the season. If they have more than a 36,000 capacity at the start it'll still fit more people in it than the old Lane.
I went past it every day on the train for a week, two weeks ago, and was thinking it did look a long way from finished (and really out of place in the neighbourhood it's in, but that's not really the issue).
Other teams have had lots of away matches at the start of a season when they've not...