When I was a kid we were often cooped up, due to one of us having an illness that was contagious (so we all were in lockup) or bad weather. My mother gave us things to do that included - paper and crayons, and told us to think of our favorite story and then draw it. Books to read and then we would act out the stories, each of us taking a main character part. Stuff like that.
We also were given old handkerchiefs (I don't imagine those are still around) and taught to sew them into little pockets. We filled the pockets with dried beans, then seamed them up. We had a lino square floor in our laundry room (which was quite large) made of different colored squares, and so my mom put numbers on the squares and we made a game of tossing the bags from behind a line to get certain squares. We also were given spare frying pans and we could toss the bags from the frying pan to one another, to be caught in the pan. Or a bowl was put in the middle of the room and we'd each get in a corner and take turns tossing our bags (each of which looked a little different) to try to get them in the bowl.
And then there's using the bags like jacks - you toss them up in the air and do a series of repetitive actions, before you catch it. Toss. One clap. Catch. Toss. One clap plus pat tummy. Catch. Toss One clap plus pat tummy plus spin around. Catch. Toss etc.
Our basement floor was cement, so we would chalk hop-scotch squares on it and play hop-scotch with the beanbags.
Don't know how helpful any of that is in a modern world, but... maybe?
We packed up most of our books, but I've found a few kiddie books I'd meant to send to people back in the States. Perhaps I'll sanitize them and see if the mum across the way might want them. I thought they had gone, but I saw them all yesterday.