Yes, we have downsized by about half. We sold our summer house in Denmark, and are so relieved to have only one house to take care of. We had not planned to ever sell the house, so we'd gathered heaps of books in the 24 summers we spent there. It was fun to give boxes of books to family and friends in Denmark. We had a lot of art books that a very happy antiquarian book dealer in Ebeltoft bought, which payed for shipping home some favorite books.
My husband taught art for 28 years, so slides of student work and lecture slides and slides documenting techniques are what he has had to organize, and to find homes for in libraries and museums. It is a great relief to know they are in the right places, and not left cluttering up the basement, forgotten and unseen.
We did not downsize when we moved here six years ago. In a small town in PA a big Victorian is very reasonable, and we enjoy all the space - and all the stairs! The stairs are a treat for me. I go up and down all day with ease. On floors I shuffle and limp, except on lucky days when my feet decide to work. They always work on stairs. It is good exercise and a good boost to my confidence that I can at least still do stairs. I would not have that if we had been more sensible in our choice of a home for our dotage.
Re. chat: You do meet some bright and interesting people in chat, it is not always just chit chat.

All the best,
birte