Oh, I would definitely utilize the main floor level for your sewing studio. We bought a Victorian house and after hubby died, it took awhile but finally I decided to convert formal living area to my studio with two long folding tables and plenty of room to move around in. And, I love it. There is a large adjoining den and also a dining room to serve for meetings and entertainment. Family dinners are held at childrens places now as it is difficult for me to do them at nearly 80 yrs. I have 1500 sq feet overhead that could be finished out but don't need it. My oldest son just moved from a tri-level to be out in the country and on one level, closer to dau and SIL. He is looking forward to when they will not want to negotiate stairs.