Yeah that video is great. A lot of fun insight.
You should join back up and get practicing! As for day/night cycles, no not yet. I'll be honest and not give you any ridiculous expectations, I don't see it coming until at least Spring next year. They've already said it's not coming in time for Le Mans (this race)
As for format, stints and stint length depend on the car and its fuel load. Some cars can do almost 2 hour stints while some go from full tank to empty in 45 minutes. This track is going to be intensive on fuel so there's that. I don't know offhand how much the GT1s carry as far as fuel, nor how fast they burn through it but my guess is around an hour. So likely it would be 24-25 stints. Usually we prefer to run two drivers in pairs for four or five hours, alternating each stint. I find that strategy works best.