I don’t have specific advice for you on the details of downsizing, but I offer this from my own experience:
My Mother held onto her 4 bedroom colonial with lots of land for years after all of us had moved out. Here memories were there she thought. She liked to garden. She spent a lot of years getting the decor how she wanted it. She finally, in her mid-60s, decided to sell and move in to an over 55 community. Once she was in and settled it was like a giant weight was lifted off her shoulders. She now had the time to get back to her crafting and all of the other things that actually brought her joy, including more time for her grandkids. And her memories moved right along with her. 🙂