I tried to over winter 4 in pots, 1 was Intrigue patio tree rose, cold and dark, watered them about once a month. That may have been the mistake but had read that they should be moist (not sure how to achieve just moist). They broke dormancy in February and I hadn't checked until at least a week later, they were a sickly yellow/white. I kept 1 alive but it was not doing well when I planted it out. I had cut off the new growth and buried the crown, most likely it is dead. I may have watered when we had a warm up for a few days this winter but the plants were in a place with a little indirect light. I have read that breaking dormancy is a problem with trying to over winter them.

Tanline: Although I haven't overwintered a tree rose yet, the fact that it is a carpet rose bodes well for you in that they are somewhat hardy...should winter well inside with temperatures as close to zero as possible. For insurance, have it potted in a large pot...moderately moist soil...wait until the last week of October (more or less) before putting it inside...and loosely enclose it with plastic (this helps prevent dessication and provides a buffer when vehicles are brought in and out of the garage in extreme cold weather).

Once it is in a larger pot, let it slowly dry out (don't want bone dry)...you shouldn't need to water it until middle to end of March. Keeping the soil on the dry side inhibits breaking dormancy or at least slows it. I've done much more damage to potted roses by over watering.

To help determine if the rose needs water in the winter (or for that matter year round) install what I call a "tattle tail" when potting it up. A tattle tail is simply a thicker piece of very absorbant cloth (such as Sham Wow)...Lee Valley Tools sells an excellent absorbant cloth...that is installed into the drainage holes on your pot when you are placing the soil in the pot...it should extend at least halfway up the pot. It acts as a capillary drain (photo shows it doing its job) as well as can be checked by hand.

If at all moist, don't water...wait until dry and then water until it comes out the drainage holes...a good soaking.

I only have hardy shrub roses but I have read about overwintering hybrid tea roses in our climate. One method is to dig up the rose in the Fall, dig a trench and lay the rose down into it at a 45 degree angle and mound it back with soil. Mark where it is so you can find it in the Spring. Dig up and replant. Seems like a lot of work, so I've never done it. ;)