I'm really not overloaded, I have a very agile team and we usually don't take more than we can manage.

But saying you can always, with 100% certainty predict what blockers may arise in the whole next week is a kind of clairvoyance I'm not sure is possible. If it was, we wouldn't need daily standups in that second week.

And, once again, Kanban is a thing.

Please, let's just not use "all work being done" as a metric for time off.