Rather than trudging home through the snow carrying their bags, Lorelai organises a sleigh ride home for she and Rory (and none of their friends, like Luke or Sookie or Dean or Lane … but maybe she didn’t want to seem like she was playing favourites, or the company would only allow one sleigh ride home). I’m not sure how they got to the inn with their bags in the first place. Perhaps someone gave them a lift?
The Bracebridge Dinner was originally going to be held on a Thursday night, and that would mean this was Friday morning, and Rory should be going to school. It’s likely it was moved to the Friday (meaning that it replaced the usual Friday Night Dinner with Emily and Richard), and it’s now Saturday morning and Rory is on her break. It can’t have been a weekend night, because Dean and Lane went to school the same day as the Bracebridge Dinner.