Hello y'all'

I had a beautiful crimson mandevilla in a pot that I brought inside a few days ago. Believe it or not, it was still blooming on our front porch, and I wanted to save it from the cold. Unfortunately, it has been "pouting"; leaves are drying up, in spite of watering and blooms are shriveling as well. I kept it in the laundry room at first, which isn't overly warm, then moved it into the dining room. We heat with a wood stove, although I'm usually careful about not putting plants in the same room, and we humidify our home....what's wrong and why is it sad???? Should it be cut back and moved to the basement with the begonia tubers? This plant was beautiful, and I HATE the thought of losing it....it can't stay outside! What shall I do; need advice!