Seniors in France

Please elaborate. I don't understand your question.

You can walk as much or as little as your want or need to.
You can set your own pace (if you are not on a tour that has deadlines, times, dates, etc.)
I love walking around the cities and towns.
Do you know which places you will be visiting? Also remember that you can
hop into a taxi if you get tired, or a bus or in some places the metro trains.
Hope you have a wonderful trip - take your time - sit on a bench and watch the cities
and towns.
If you are on a tour, you can always decide to wait on a bench or steps while the tour
members "do their thing"
Hope you have a wonderful trip.

This is exactly the situation we hope to be in about 15 years. Our thought is to do a river cruise. That way, you don't walk a lot. Your hotel moves down the river. You can do a shore excursion, and go into town and sit at a cafe.

What I would do is pick a river cruise in an area I like and inquire if you can do bus tours to the towns. Do you like museums? Art? Music? I think many of the river cruises work with older travelers.

Sdslater, it would help of you could elaborate on your plans. Are you looking at a tour (perhaps a RS tour), or are you travelling on your own? Are you just visiting Paris, or going to other places as well.? It's hard to advise without more information.

Some tours offer both standard & easy walks, but rarely advertise the options. Ask when planning. Or skip the tour walk & do it yourself. There are apps that will guide you in some places, or get a good guides book-- Michelin Green Guide & Eyewitness Guides are especially useful because they provide city maps for recommended walking routes.

I'm guessing that the OP is referring to the walking designations shown on the RS tour daily itineraries. The only alternative to the moderate walking days is to not participate, or perhaps only do half of the activity and sit someplace and wait for the group to return, if possible. But you have to pretty much do what the tour does, that's why they publicize the walking required, they won't make special accommodations if you cannot.