Need advice on quantity cooking: chicken and baked potatoes

Next Monday we are attending a funeral for my father. When sending out the announcement via email to all the family, I impulsively offered to have a dinner at my home following the service. Everyone has accepted (which I did not expect) and I need urgent help from the readers.

I plan to serve between 20 and 30 adults and would like to make chicken cordon bleu’s, baked potatoes, salad and rolls. Questions: 1) Can the chicken be prepared the day before? 2) Do 20-30 baked potatoes need more oven time than 2 baked potatoes would? If so, how long should I bake them? 3) Same question for 20-30 chicken bleu’s - how long & what if I throw it ALL in the oven the minute I leave and set a start time? I shouldn’t be away from the house longer than 1-1/2 hours.

If my menu doesn’t sound good, does anyone have any helpful suggestions? I am hoping you can all help with ideas.
Many thanks,