Hi from Wisconsin,
Personally, I wouldn't leave Paris. I would try to eat myself to death on croissants and baguettes. And then I would try to revive myself with a pitcher of wine.
There is an excellent bakery in the Marias. It is at the T of Rue Vielle de Temple and Rue St. Croix de la Bretnoneire. This is not a tourist destination, and the people working the counter don't speak English, but you don't go there to chat. You go thetefor morning special of a long black coffee and a croissant, the return at lunch for a fresh sandwich so you can eat in a park, and then return in the evening to buy a rouge tort or some other pastry. All of the above will be excellent. The local restsurants source their bakery needs at this place.
Go to Chartres and its world famous cathedral. It has a nice old town, the cathedral is nicely placed on the hilltop, and there is good food. Besides, I bet Notre Dame in Paris is closed for repairs.
Ah, go to St. Denis. The basilica's rose window is stunning. The tombs of the French kings from Pepin on down the line minus Charlesmagne were burried there. It is on a Paris subway line. You might have to change lines to get there depending on where you start from.
Forgive my spelling but tour Pere Lachaize cemetary. The headstones alone are worth the visit. But Alice B Toklas is burried there. Famous for her trail mix.
Paris, so much to do.
Wayne iNWI