In my opinion a lot depends on your facilities. How much room you have indoors and outside is important, the more the better, but also how they are laid out. Where you are weather should not be a big factor, that outside should be available pretty much all the time they are awake if you give them access to it. To me that is big advantage you have.
I have an 8' x 12' main coop and two separate 4' x 8' shelters I can use to house them in when the main coop starts to get crowded. I have over 3,000 square feet available to then outside practically all day every day. Room is not an issue for me.
I've noticed my chicks avoid the adults during the day and at night. As long as they don't invade the personal space of the adults they live in harmony. If the adults are under the mulberry tree the chicks may be under a plum tree. They may later switch but they won't be under the same tree at the same time. At night my brooder-raised chicks do not sleep on the main roosts with the adults. Some broody-raised chicks might but all of then don't either. I don't care where my chicks sleep as long as it is predator safe and not in the nests. I think a lot of problems occur when people try to force them to share a space too small, either during the day or sleeping together at night.
My brooder is in the coop so the chicks basically grow up with the flock. When they are 5 weeks old I just open the brooder door, that's it for integration. Of course I pay close attention for a few days, especially when they wake up in the morning, but it is just not a problem.
You are not in the same place. Your facilities will look different and yours were not raised from hatch in the flock. Without knowing what your facilities look like I think you are in a pretty good place. I just do chickens, not ducks, I don't know how much that matters. My approach would be to let them out in the morning when you can be around to observe and see how that goes. Sometimes the easiest approach can work, it does for me. But be prepared to rescue them if you need to and try something else, maybe the panic room approach or just give them more time. It can be a good technique but there are others.
The basics for me are to base your actions on what you see, not what some stranger over the internet like me tells you, and let them work it out at their pace as much as you can. Good luck!
