Paris: left bank memories near Pantheon/Luxembourg Jardin en Decembre

I've never been in Paris at Christmas (some year hopefully), but Notre Dame is very close and should be especially beautiful then, before or after dinner. Lots of nearby sights: Ste-Chapelle, Cluny Museum, Luxembourg Gardens, Pantheon, rue Mouffetard market, Arenes de Lutece, Ile St-Louis, etc. What you can see and do depends on how much time you have and whether you're there during the day or just around dinner time. Just walking around Paris is wonderful, and you'll be in one of the most beautiful parts imho. Joyeux Noel!