I would like to start dinner with a clear soup (with a homemade stock base), not a creamy one. Any suggestions? I don't think there will be time to make a consomme.
For years I have been making stock in varying strengths and freezing it. Just recently we really reduced it to a very concentrated strength and froze it in ice cube trays. It really frees you up to do lots of things. Thanksgiving is so much easier if you can do things like this in advance. We use it for so many other things as well. We use it to cook rice. When my daughter is sick her favorite is to poach a boneless skinless thigh in it and squeeze lemon juice on it. Etc. Save yourself some effort and do it in advance.
I know you mentioned not having time for consomme, but like MMH mentions above make ahead and freeze always works well. I've frozen Jacques Pepin's recipe from Essential Pepin before and since the process is filtering out all of the fat while concentrating the flavors, it freezes even better than normal stock. However, I would suggest waiting until the day to season.
Mushroom and scallion soup. Basically those two ingredients, plus a good clear broth (chicken or vegetable) and a couple spices to taste (pepper, ginger). I've lost my old recipe, but there are many out there. Simple and good.