I dropped in to Denbies today since I was passing. I missed the tour but had a good nose around. The place is huge, a point to which the photo here does not do justice.
I tried many different Denbies wines but did not buy any. The person at the desk told me that their Surrey Gold is the biggest selling English still wine, and that most of it is sold to retail direct out of the Dorking site.
The place is vast, with shops and a place to eat as well as the vineyard tour. I just enjoyed wandering the vineyard gawping at the scale and wondering.