Oh gosh, not had one of those for a while, even just one day let alone three!
I would have a lie in, then feed the dog & cats, then go back to bed with a cuppa.
I would then get dressed and sit in the garden with coffee & breakfast.
A walk with my dog into town and wander around the market, maybe buy some treats for lunch or dinner, some nice plants for the garden.
Do some craft like crochet or papercutting.
Watch a film, or a series I've series linked.
Cook a nice dinner of something that needs a bit of prep like steamed Korean buns or try making pasta and make some ravioli, and eat whilst watching a film. Wine would be involved ;)
The next day, start pretty much the same way but maybe get up earlier to walk dog earlier and for longer through the countryside.
Come back for coffee and brunch, or go somewhere for brunch which allows dogs in.
Do some more craft. Some baking.
Cook a mini roast for dinner. More wine, another film. A long bath.
The next day would be much of the same. Maybe go to the cinema?
There would pretty much be the same thing each day, dog walk, lie in, dinner in front of tv, wine.
Or, knowing me, I'd be on here living vicariously through all of you ;)