I don't consider myself an expert by any means, so don't take this as gospel, but I think that if she were mine, I'd plant and mulch her. Clematis are pretty hardy and the only ones I've lost to winter cold have been those that are marginally hardy in my zone. I've done both the inside and the outside thing with good results. If you keep her inside, she needs a small amount of water over the winter - I did kill some roses by putting them in a shed and never watering them over the winter. She'll probably be fine no matter which way you go.

I would put it in the house near a window & treat it as a house plant. Since you only have the one it should not be that much work. Letting it have sun all winter will give the Clem a really big root system by spring. Once the weather warms in spring you can harden it off a little at a time then plant it & watch it take off. The Clem should have a strong start & great flowering season.