A. You can't.
Any time you tell someone you don't want to be with them, it's gonna hurt a little. So depending on how understanding your family is, you could try the blunt truth -- your desire to start some of your own traditions with friends and no traffic jams. If this logic won't fly with your clan, and you value family ties, then you'll have to do the compromise thing. Invite the grandparents to join you and your friends at your house. They'll either accept and you all win, or they'll decline, but at least you asked. Another option is to create a holiday rotation schedule: one year friends, the next year family. Finally, if you have the stamina and really love a party, or two, you could try inviting the grandparents over for brunch and going to your neighbors' in the afternoon. My family and I do two Thanksgivings -- lunch in New York and dinner in New Jersey. Not ideal, but everyone's happy (and full), so it works, and we do have fun.