Dear Sherry,
Is it possible to use the gas logs only once in a while, to move the harp to another location in the house, to let laundry hang dry (drip dry) somewhere in your home and to keep a pot of hot water steaming on the stove on low? What about opening a window a tiny crack to allow some fresh, damper air in? In some countries, the double-paned glass windows come with a tiny extra window for allowing fresh air in.
Perhaps a guitar humidifier could be placed carefully in the soundbox hole of your harp. It is a small rubber tube with a wet core inside.
A portable, digital, battery-operated humidity gauge is a nice tool to have. We keep one level of our home at 65-66 F, no hotter, with various instruments around, and just wear woolens and lots of layers.
Sincerely yours,
Susan Abken