Depends what you mean by "arrive at rope drop". If you mean pulling into the parking lot when the park opens, I'd say 60+ min. If you mean getting on the monorail when the park opens, I'd say 45+. If you mean walking up to the MK entrance when the park opens I'd say 30+ min. If you mean you're going to be at the MK entrance 30+ min prior to park opening, I'd say 1-30 min.