Colouring in a massive cardboard box each, ask for one for free from a supermarket. Once coloured in, open up and create a den. You can also make pretend iPads/laptops/phones/kennels for a favourite dog teddy/mini zoo for their animal toys out of cardboard
buy a roll of wallpaper lining paper, stick to the floor with masking tape and let the kids decorate. One sheet each day until a whole room’s floor is “redecorated”. You can also do this with walls but it doesn’t stay on as well!
alternatively buy giant plant pots and posca paint pens
kids always love helping with grown up tasks eg the washing up, just make sure to line around the sink with loads of tea towels or alternatively have them sit on the bathtub with a washing up bowl each
mine used to love doing the washing of their dolls clothes too, I’d purposefully roll them in mud and let it dry then give my kids a washing up bowl/brush/pegs and washing line in the back garden and let them crack on
sidewalk chalk if you don’t mind them sewing on your drive, then give them a hose pipe or water and brushes and they scrub it off.
walk everywhere to stretch out activities eg wake up, make breakfast together (eg kids butter own toast) clean up together, walk to library, back, snack, clean up. Make picnic lunch sandwiches together, then Walk to playground. Playground, picnic, games, walk back. Quiet time. Garden chalk, audiobooks and colouring whilst you cook tea for them, tea, Lego, tidy up together, bath books bed