There was a Dragon Quest: The Adventure of Dai 2020 anime/game livestream that showcased information on the new anime remake and the 3 games coming out. I have taken the 2 anime development trailers they have showcased from the nearly 3 hour livestream, and included just the Dai anime remake development trailers for your convenience.
The first one was about 45 seconds and at 1920x1080.
The second one was 1m30s and I had to crop it to show just the development trailer because part of the video screen showed the team talking about a certain scene, so I cropped that out. Luckily the trailer screen was actually a good size, so the quality is good, but I had to downsize it to 1280x720.