I woudn't lose hope about being switched. We booked our 1st DCL only 2.5 weeks before sailing and it was for 7 nights. With a 6 and 2 year old, I was very worried about the dining since we got 2nd seating. We were switched to main dining 4 days before sailing. We sailed in July when ships are full and have lots of kids on board. Our 2nd 7 night sailing we booked about 2 (or maybe it was 3) months prior to sailing and same thing, moved from the waitlist to main dining.