Bumping!

Hi @Rose Beginner Zone 9b LA

I've never planted this one but I found some discussion of it in this thread, including by someone in California if that helps:

https://www.houzz.com/discussions/3841321/please-post-pics-of-your-jubilee-celebration-rose

Edit: just noticed another discussion about it here. It doesn't seem to get huge even in warmer climates:

https://www.houzz.com/discussions/5372020/jubilee-celebration

We have grown Jubilee Celebration at our home for around 10 years or so in central California in USDA zone 9b and Sunset Zone 14.. It was planted in an area where it got filtered sunlight for the morning hours and full sunlight for the rest of the day. This rose eventually grew to around 4.5 feet tall and around 6 to 7 feet across. Our JC filled out as it grew and assumed a dome shape at maturity. It had flowers from the top of the plant nearly all the way to the ground. It was one of the most satisfying of all the Austins to grow because of the plant form, the quick repeat, and the number of flowers produced. To top it off, it has a nice, strong fragrance. Most of the flowers tend to have shorter stems, so it is not as good as a cut flower as are other varieties.

This photo was taken 5 years ago or so, so it is not as large as it was most recently. We have since moved this rose to a different location. You can see a bit of 'Lady Salisbury' (light pink in the lower right corner and Prospero (purple) in the upper right corner. I would give JB as much room as you are able, as it grows into a beautiful plant form if given adequate space.