I had 3 bored children and a husband who worked away during the week. We ended up with A System during their primary school years. (A System is even better than A List)
At the start of the holidays everyone wrote on strips of paper Inside Things To Do and Outside Things To Do. Outside had a price limit.
All were vetted by me as appropriate so “Feed youngest to the swans” for example, got weeded out.
We had a coloured piece of paper on the fridge with the heading This Week on it.
On a Monday after breakfast each child would pull out a strip of paper from both jars and blutak them to the Week page. It became quite the big deal. No substitutions or reselections unless weather prevented it. No arguments.
Then we had a mix of indoor, outdoor and (importantly) free stuff that we’d do over the course of that week.
There were things like Ride The Whole Bus Route At The Top, library visits, scavenger hunts, blanket forts, indoor picnics, lots of films/audio books while colouring etc, and the city we live in did lots of free things for children too, so I got on the appropriate mailing lists to put about them.
We also had Film Festivals (think Harry Potter, Star Wars, Disney) - one day was making posters, making tickets, then the next we’d make a “snack kiosk”, each child could invite one friend if they wanted. They’d roll dice to see who got to be the usher showing people to seats with a torch in the darkened living room etc. That killed quite a lot of time, thank god.
Paddling pool at night with glow sticks was another big hit. (Bubble bath in the dark with glow sticks is hilarious).
If you have a small tent you can put up in the garden, that also keeps them busy and quiet for ages.
Best of luck!