Thanks, everyone, what a timely posting!
Just got back from the SIL's, who has the most enchanting setup. A little black modern woodstove with large window in the living room, feeds to the built-with-the-house hugenourmous solid brick/block? chimney. Heats their whole two story home. And it is so airtight my asthma stays quiet.
However, setup for here would be around $3 grand. Our house has the fake chimney- fireplace insert with what is probably single wall pipe (I had to fix it when we moved in, builder would've killed us the way it was in if I hadn't had it inspected). I'd have to have two stories of double or triple wall pipe, new chimney cap, and rebuild the hearth and floor. And no, dear, I don't want a stove from the flea market. Did I not make myself clear on the asthma for the last two decades? (sorry rant)
I didn't even THINK of checking with the insurance or codes! Yikes! Since we'd only need it two months, maybe a few weeks more, here in the Atlanta area, I think we're stuck with the all-electric home.
More practical, affordable and DIYer - I'm looking at the wall mount solar air heater boxes. The bedrooms face full sun south....
Thank you all again for simplifying the explainations of all the considerations.