I may be being a bit senstive about the word timetable at the moment...some of our childrens siblings were sent home with a very strict timetable from their school and freaked the parents out
The church representatives this morning were quoting nuns and monks who are used to self isolating...they emphasised the use of routine and rhythms in the day to keep us on track and of course if you have children with ASD they will expect things to stay the same as much as possible . I love the fact that this crisis has brought out the creativity in people and your ideas sound brill ....how many children will you have ?
I guess there are things you need to do wash hands on entry/ snack time/lunch time/ afternoon play so seeing to the childrens health and care needs this will give you a basic structure and then as you suggest i would be outside as much as possible
(not sure this is at all helpful,,,,,just my ramblings !!)