I think it’s great (inspirational!) you’re traveling with your family, and happy 40th😊 Your post struck a cord with me when I read it. I’ll be 43 myself in a few weeks, and have a 4.5 year old and a 2 year old. The 4.5 year old is a calm, reasonable kid, although a bit anxious, and the 2 year old is a wild card. She’s either completely calm and interested in the world around her or a total mess, which is almost always correlated to her being hungry or tired. We are prepping for a trip to Switzerland and Italy next year, so I feel your trepidation minus a couple of additional kids. It’ll be my kids’ first international trip, and we are going to go with extended family so lots of extra adult hands. Smart move on the babysitter part 😊 We haven’t done a lot of domestic travel with the kids - a few long distance (12+ hrs) car rides, etc, and will be taking them on a plane ride in a few months to the beach as sort of a trial run. We also have been trying (for their whole existence!) to take them out to shops and restaurants and focusing on manners and behavior. Sometimes, with more success than others. 😊 Now, finally, we have a good handle on what their tolerance levels are, which helps us massively in managing them - a 7pm dinner that lasts 2 hours isn’t happening, but a breakfast or lunch or 5 or 6 pm dinner that lasts 2 hours and we have a couple of tricks in a bag...is doable. They’ll be off their games for at least a bit when we arrive due to time change, so we’ll have to sort out what makes sense. It might be a pizza in the room for a few days for us!
What do YOU want out of your trip? If you feel better about going someplace that you’ve already been so you can see a bit of a different side of the city and not feel like you’re going to miss out by going someplace new and potentially not being able to see...say a museum or something....then Paris (for you) is the way to go. Find child friendly excursions, go to the park, walk around, visit cafes, get snacks, take the train or ride a bus, etc. For me, I have not been to Paris, but have previously been to almost all the places I’m going next year in Switzerland and Italy (there are family reasons for this, it’s a bit of an roots exploration trip...plus some fun outings in Italy). I fully recognize that I won’t get to do all the in-depth sightseeing that I want, and that’s fine with me. I’ll just do different things - like a park instead of a museum or a toy store instead of a boutique. It’s a different type of travel. I feel more confident in my decision making on the cities as I know a bit more of what to expect logistically (although I am now in the throes of how do I deal with a metro and a stroller?) so....
For me, I’d rather be someplace warmer in December and January so I’d want to go to Italy if I was focused on Europe. I would also want to pick somewhere I’d already been - to be honest - so I wouldn’t feel like I was missing out by managing the kids. I also think about my 4.5 year old - it’s not like he’s going to remember much of this trip - your 7 year old probably would. I’m guessing they are going to be massively impressed with visual things or transportation - a bus, a train, a boat, a castle, a cafe with a chocolate crossiant, etc. Out of the places I’ve visited (again, haven’t been to Paris), for me, Rome or London fits that bill very well with stuff to look at and experience. But, you should do you, and if you want to go to Paris, figure out a way to make it work for you so everyone has a great time! A friend once told me, it’s not really a vacation with young kids - it’s just managing them in a different city. I sorta agree, yet struggle with the idea that my life goes on hold until the kids are teenagers, so...I think about how to make it work.
So, in the end, commentary from someone without a lot of kids who hasn’t traveled a lot with said kids, but is sorta in the same boat. Good luck and have a great time with whatever you chose to do!