Nearly all of the LH flights in my itinerary became available T-15 some time between 3 and 6pm (local New York time).
The ANA flight was booked at approximately 630am on Nov 19 (flight was on Nov 29).
The LH FRA-IAH (A380) was booked the night before the flight.
Luckily, I'm UA platinum, so I was able to book as flights came available and just swap out the segments that were just placeholders at no cost. Otherwise, doing a similar itinerary would either require a lot of luck or stomach for hefty fees.
Booking another trip now for just after Christmas and availability is def a lot worse. Still, some LH/F is being released T-15 in the afternoon. It seems LH is limiting award space on their premium F. For example, IAD and ORD have 7 F available (expertflyer) and LH is not releasing space yet. JFK has 8 F seats open and only 1 is available for award. Meanwhile, on routes to FRA with the 343 (DTW) or 333 (SEA), they will release 2 at T-15 if it is there are 8 F seats.
Good luck! The persistence is worth it.