It's actaully pretty easy. All depends on the condition when you bring it indoors. The best chance would be a pretty pot bound gardenia in a well draining mix. The key point indoors in winter is to avoid warm and dry but no sunshine. The best way to judge when to water a gardenia is by feeling its weight. The pot should be much lighter compared to a new watered one.

Ed,
Since you have a problem bringing them in potted up for the winter, why don't you plant it in the ground?
Your in Northern MS, zone 7B, do you have a morning sun location?
You could even plant it in an afternoon sun location if you could plant something near it to shade it in the afternoon heat.
Gardenias are like rhododendrums, they don't like it inside, they love it outside.
So, plant it in the ground now and mulch it real good and watch it grow!
If you have clay soil, make sure to mix alot of manure real good in the soil first then plant it up on a mound, above the natural soil line, then mulch good. This improves the drainage.

I am am very tempted about the outside idea....I have an August Beauty planted outside that seems to be doing well. Not sure about this variety, but the limiting factor is more what are good sheltered locations with sun.

will my gardenia tree survive the winter. I live in PA in Bedford county