Margie ...
Although I have not visited the Peggy Rockefeller Rose Garden, I am very familiar with the people involved in the selection of the roses used to replant the garden with roses that do not require a lot of TLC in that climate and the how and why a given rose was selected for the Garden.
In zone 7 with the marine influence, you are actually gardening in a rose friendly environment as far as cold hardiness is concerned. That was the information I was seeking. That tells me you have enough time for the rose to settle in and get its root system established before the coldest part of the year.
The rose will probably put on some new foliage once the root system is working, but creating that new foliage will use up more of the stored nutrients in the canes than the new leaves will be able to provide to the plant through photosynthesis. Oh, well.
I don't think the rose will have any long term problems as long as you keep it moist and don't allow the canes to dry out. The top growth may look lousy at this time of year compared to your other roses simply because the plant is busy growing roots.
My preference is to remove very little wood from modern roses in the fall. There is always someone else who will tell you to cut it back because then the plant will have less top growth to support. Since I can't really see the plant ... even in photos ... I can't get a feel for it. I am certain you can and will let the rose tell you what it wants to keep.
It seems like you know what you need to do, but just came across something you had not experienced in the past.
Smiles,
Lyn
Ooops ... spelled Margie's name wrong. Had to fix that one.
