Sewing room in the basement
Why not use both spaces. You can sew in your upstairs room with new lighting there and have things you do not use all the time like your stash neatly arranged in the basement. I use both and prefer to sew upstairs where it is warmer. I have converted my dining room to my sewing room. Wish I had a bedroom to use but I have 2 bunnies that have taken over a bedroom. Going downstairs to get things is a great way to get my exercise and my body doesn't mind that a bit especially during these cold winters in Michigan. Just a few thoughts.
Lea in Michigan