I have been able to secure 6:45 MTD reservations for all three of our cruises since the restart. Harmony 3/22, never waited more than 10 minutes and had same table/staff every night. After night 3, they just waved us in. Personally, I don’t think 6:45 is late and 5-5:30 is way too early for us. There will be plenty of time to see shows and, frankly, none of them are must see IMHO.