So... two weeks after she arrived, the work has FINALLY finished, and Madame went into the ground yesterday! Happily, we had just had two days of rain, so the ground was nicely soaked after this very dry spring and temperatures are nice and balmy.
Although confined to her pot, Madame lost no time in making herself at home and put on over 30cms of new growth. Now, 24 hours after planting, she's looking happy, and so am I; thanks again for all the excellent advice.
Now to await the first bloom... or am I having a rush of blood to the head?
S.
PS. It may be worth adding that I emailed Peter Beale's two weeks ago to ask for their advice on planting, but have yet to receive a reply. So, customer service not ideal at this busy time of year, but on the all-important plus side, the rose was sent promptly, arrived in excellent condition and seems to be hitting the ground running (so to speak...).