the gardeners world website list some smaller ones in this article.

https://www.gardenersworld.com/how-to/grow-plants/white-hydrangeas/

I have an oak leafed hydrangea with brilliant white flowers the shape of fat lilac flowers.It is flowering now and is beautiful. It is still compact after at least ten years - about five feet max. Have to admit this is the first yer it has been magnificent rather than just ok, but worth waiting for.

Thanks Seaburn girl. Have had a look at that website but wondered if anyone you give a personal recommendation.

Steragram- you don't happen to know the name of your gorgeous hydrangea?

All I can remember is that its an Oak Leaved Hydrangea. (Quercifolia) I've had a look on line and the flowers are like Gatsby Gal but that pic doesn't do it justice.
Put Hydrangea quercifolia images into Google - there are two or three there. Mine took a very long time to start flowering well but if I'd known how spectacular it was going to be I'd have planted it in a more prominent position! All the flowers are on the South side.