Maggie, the house the kids have found is gorgeous! I can't imagine needing anything that big - especially as the kids are beginning to grow up and leave home. But everyone has different tastes and desires.
Dody, that house is mighty big LOL But since you're taking over the whole upstairs and can plan it the way you want then you're good to go.
Design item to keep in mind. I pour through Cloth Paper Studios magazines and most all of the artists seem to have the same consensus that outlets in the ceiling so the power chords drop down to your work surface is a must-have. They feature a lot of art quilters.