A few years ago all tree roses were made by grafting a standard (the term for the tree portion) onto a root stock. After it took, the rose you buy was double budded (on good tree roses)on to the top of the standard. What you had was a rose plant with two grafts, one at the base and another on top. In zone 5 they'll die during the winter unless planted in a pot and moved into an unheated garage or shed during the winter, or laid over and buried.

A few years ago Jackson and Perkins developed a standard on it's own roots. The rose was double budded onto the top of this own root standard. This resulted in a tree rose with only the grafts at the top.

Baily's has developed a tree rose with no grafts. These are labor intensive as they require a lot of care to make sure they don't sucker and grow straight. They are rather expensive costing up to $70.
It's only available in one variety/color right now but is advertised to survive to temps down to minus 40. Mine died last year and temps only got to minus single digits here although the late freeze probably did it in and it was planted late.
The replacement is planted in a large pot so it can be moved into my unheated greenhouse for the winter.