They will definitely let you in significantly earlier than 7pm, even with just hard tickets. However, we have been on Ultimate Park Hoppers past 2 years (and again this coming Oct 16), so we take a nap, enter the park about 4:30pm, eat dinner, then find a CM with wristbands about 6pm. At that point, the "day guests" are no longer allowed to board the rides. So, between 6-7pm, we simply jump from ride-to-ride with little or no waits. Finally, we stay till midnight - watching the later parade and the show at the castle (Cinderella's Surprise - I think there was a late show after the fireworks). They were still doing trick-or-treating at midnight past two years. DD5 had no trouble going strong till midnight (with the nap).