I normally go for a walk, do my work on my iPad, run errands, get groceries, catch up with friends on phone or facetime, audiobooks etc. My DH inevitably takes a nap especially in winter. My kids participate in tournaments that can last for a whole day.
My minivan is fully stocked - camp chair, blankets, pillows, hats, parka, umbrella, cooler, reusable grocery bags, books. And no, I do not leave my kids and come home. I am always close by.