An ancient thread, but......................
I was at a wedding at Tortworth Court recently (right beside the M5, not far from Wotton-under-Edge), and to the rear of the hotel, looking down onto the M5, there were several trees, absolutely loaded with mistletoe. The ground underneath was absolutely smothered in fallen berries.
I think it was an ash, from memory, but one in particular had many hundreds, possibly into 4 figure number, of discrete mistletoe plants on it.
If anyone is in the area and is curious, assuming the trees are still alve and there (especially given that the major one was probably an ash), it should be easy to take a walk and see the trees. Check their website, there could well be a footpath through the grounds and it is so rambling that non-customers should be difficult to spot. Or book lunch and enjoy the grounds in full.