I have a college friend who lives in the Carre Rive Gauche, just blocks from the Louvre and Musee D'Orsay. In 2019 (Christmas and New Year's) we spent about 12 days at her apartment while she was back home in America. We just stayed there again while she and hubby went to Scotland.
Day 0: Arrived at CDG and took RER to Paris. Got groceries at Monoprix, settled in, and discussed what we wanted to do the following day. Baby up for hours in the middle of the night. O_O
Day 1: Walked the jardin des tuileries, went to the Eiffel Tower (not up, once was enough for me!), walked along the Seine. Baby up again from 11 pm to 2 am. O_O
Day 2: Went to Chantilly to see the chateau, gardens, and horse show. Show was in French and we absolutely loved it. The scale is perfect, not too many people and wonderful dressage and trick riding. We went to Versailles on our last trip but it was winter so the gardens were lackluster. The Chantilly gardens were LOVELY and we walked ALL through them and saw some of the horses in temporary pasture and were able to watch them for a while. All the horses were gorgeous! My only regret was we didn't arrive with enough time to really get to do the horse museum AND the house AND the gardens. Also chateau was, of course, not stroller friendly.
Got melatonin for baby and we all slept through the night!
Day 3: Took train to Epernay and toured Moet & Chandon, did a champagne tasting at a local tasting room, then drank more champagne at the BEAUTIFUL maison of perrier Jouet. Our Moet tour was in French so I probably only caught 25% of it but it was still amazing to see the wine cellars and of course taste the champagne. Perrier Jouet was like instagrammer heaven, everything just lovely and lush.
Day 4: Woke up early and let wife sleep, got coffee and pastries and walked to jardin des tuileries right as it opened. Wonderfully empty and cool. I decided to go to Orangerie right when it opened at 9 am and had unimpeded views of the waterlilies and empty rooms of Renoir, Cezanne, etc. Strongly encourage this experience! This is my favorite museum in Paris and the only art museum we went to this trip. We had a lunchtime river cruise on the Calife boat and it was leisurely and delicious. In the afternoon we all went to the Paris Plages and just did a lot of walking along the Seine. We had dinner at the Maison right there and joined the Parisian crowds along the riverbank. Truly a wonderful experience.
Day 5 (Sunday): Went to a farmer's market and the Luxembourg garden to play at the ludo jardin with our boy. Very adorable but probably more suitable for older kids. Would be a total blast for kids like 5-10. Also went to the Grand Epicerie.
Day 6: TGV to Annecy, walked along the lake, went to the imperial beach, tested the waters.
Day 7: We woke up early and the streets of the old city that had been packed with people the day before were full of stalls of produce, cooked food, butchering, and handicrafts. We rented bikes and rode the East side of the lake stopping at different beaches and swimming spots and the cycling cafes. I towed the baby in a trailer and my wife had an e-bike. The bike path is totally separate from road, nice and wide, gorgeous views.
Day 8: Took the bus to a beach to play and then the TGV back to Paris.
Day 9: We decided to take Rick's advice and visit La Defence and the more current section of Paris. But we decided to do it by walking the Royal Road from the Louvre all the way to the Grand Arch (4.5 miles). It was fun to do it all in one go and watch the Arc de Triomphe etc fade into the background. The esplanade at La Defence would be a great place to do lunch or dinner, wonderful views. I went up to the top of the Grand Arche- very few people! NOT stroller friendly (there is no elevator up all the stairs at the bottom)
Overall a great trip.