My daughter lived 1.5 hours away. So not as close as you. But we loved meeting her at the farmers market at her school and taking her out to brunch /lunch. We could also drop in when she gave a special presentation.
Just act like they are hours away. One of the bonuses was that we live in a desirable major city. She loved bringing her friends especially from out of the country to visit Chicago and stay at our house.
Be prepared when they bring home laundry etc. It will happen. Being that close has advantages.
I also lived at home my first three years. My mother just gave me some space. But I did respect her and let her know when I would be home late or not at all. Again, don’t act like they are so close. Also stay off campus. No one wants to see their parents just walking around… Lol…