There is a high likelihood that you don’t pack a toothbrush to go home for the holidays (your mom will have an extra) let alone actual outfits. If there’s a formal occasion on the itinerary, you may remember to pack a nice pair of shoes. Otherwise, you rely on the good faith that your parents wouldn’t dare donate your nostalgia to Good Will and the fact that high school intramural volley ball sweatpants will always fit.
Besides, who are you trying to impress? The dog? Your family loves you no matter what and your middle school crush is married. You just want to be comfy, and comfy means t-shirts from freshman orientation, footwear that was cool in the year 2000, fleece jackets, a topknot and your old glasses. (You forgot your contacts, too.)
And if you do go out? So what. Everyone else will be in their home clothes, too.