Answer: Tree roses do need extra protection in the winter. You must protect the graft from excessive freezing, and you must also insulate the roots from extreme cold. In your zone 5 location, you will need to either bury it in a deep trench under a heavy layer of soil topped with mulch, or bring it indoors.
Unless you have a greenhouse, it is usually difficult to keep a rose actively growing indoors during the winter. Instead, you would store it in a cool location where it will rest until spring. A temperature of 45 degrees or so is ideal, it should be above freezing but quite cool. Some gardeners will keep it in a garage or unheated basement, for example. During storage, keep the soil just barely damp so it does not dry out completely.
Wait until late fall and after freezing weather has started before moving the plant so it stops growing naturally. Prior to burial or storage, strip all the leaves off. You can also trim it back somewhat if needed for space reasons. Store it until the worst of the winter has passed, then in spring bring it out to wake up naturally with the season.
Good luck with your tree rose!
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