The catch at Het Loo is distance. The palace is far enough from the entrance building that a shuttle bus runs between them, and the shuttle also carries folded buggies, which helps with small children and tired legs at either end of the day.
Everything else is covered by the one ticket, so there is no need to choose between the palace, the gardens and the Oranjewandeling. Visitors with a Museumkaart or certain other passes get in free, but only on showing the card.
You can bring your own food and drink, though not into the palace itself, and not during the Summer Nights and Movie Nights events; there are picnic spots in the gardens and around the stable square. Restaurant Balzaal and the prins Hendrik garage both offer gluten-free, lactose-free and vegan options, although cross-contamination cannot be fully ruled out for severe allergies.
