It looks far too big for the pot, put it in the ground (it should settle in nicely now before the winter) and watch it flourish. Roses need a good root run in the soil. If you do put it into the ground the only downside may be (depending on the root stock) a new vigorous sucker or two in spring - these would be a few inches near to the existing plant and a very light green in colour so should be easy to spot and then remove.
I think you will need either a bigger pot, or plant it in the ground. I have a Deep Secret in the ground which has doubled in size this year with loads of new basals. It likes to have rich soil and plenty of water and sunshine to really perform its best. It’s a beautiful rose, try pampering it and see if it rewards you.
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If you do put it into the ground the only downside may be (depending on the root stock) a new vigorous sucker or two in spring - these would be a few inches near to the existing plant and a very light green in colour so should be easy to spot and then remove.