Lucky you!!!! That's a nice space to have all to yourself. Looks like you've got a lot done so far. Keep it up and you'll be up and running in now time flat.
I would insulate and sheet rock where your sewing room will be. You might want to look at the "for sales" in the paper and see if you can't find a pellet stove for heating. We have one upstairs and one in the basement where I quilt. It keeps things nice and toasty. Just a thought, if you want to quilt out there in the cooler months.
Amy