I would probably pick a single city to explore, Washington DC, Boston, New York, Philadelphia, etc…
I would also consider an upscale train trip or small cruise ship along the East Coast, Mississippi River, etc…
I’m also a big fan of spending a week in a quiet cottage with a few little day trips. The Adirondacks or The Thousand Islands would be nice for that.
I wouldn’t force it, a quiet week at home is a great option.