Now is a good time as long as no frost is forecast for a couple of days as that will damage freshly cut wounds. While it's bare you'll be able to see the structure more easily and cut back any main stems to open up and thin it.
You can just stop it at your boundary if that's all that's needed and then go thru what's left cutting stems back to two buds. This will encourage flower buds to form. Then you prune it again in July/August taking any new, whippy stems back to 7 buds.
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You can just stop it at your boundary if that's all that's needed and then go thru what's left cutting stems back to two buds. This will encourage flower buds to form. Then you prune it again in July/August taking any new, whippy stems back to 7 buds.
https://www.rhs.org.uk/advice/profile?pid=242 for some helpful info.