Move to a farm and get some outside cats, they shit in the woods but come home overnight. If they don't they get eaten by foxes etc. so they better. We never had a litter box until the cat turned 15 and started to become less willing to go out in the snow.
Ok, moving to a farm just to get some outside cats might be slightly overdoing it but there's loads more reasons why you want to live on a farm, preferably somewhere out in the woods so you might as well enjoy the cats which come with the territory.