Wow, no one answered this in 3 months???!!!

I hope you still have the plant, and read this.

Actually, it's VERY easy to overwinter.

Personally, I sure wouldn't heat a whole garage to keep one plant. Your local utility would probably be thrilled when they print your bill each month, though.

Just put it anywhere in your house that it will get some natural light, and where temps will be between 60 and 75 at night.

When you bring it in, it will drop the flower buds and probably most of the leaves -- perfectly normal, don't sweat it. Personally, when I bring abutilon or hibiscus in, I cut them back severely, by about half, removing all of the leaves -- most of them will fall anyway, and by removing them, you leave the bugs outside. But, you don't have to cut them back, that's up to you.

Just keep it watered as normal, and throw a cheap florescent spotlight on it if the area you have doesn't get enough light.

It will do fine indoors, and should live for many, many years.

If you get any insect problems like aphids, mealybugs, or whitefly, treat it with Bayer Advanced Tree & Shrub.