How resilient is a holly hedge

We've got a beast of a holly hedge which runs all around our house, it's about 12' high, 6' wide and 500' long. It's an absolute pain to cut and getting rid of the trimmings afterwards is soul destroying.
I'm contemplating giving it a serious reduction, to about 5' in height so I can allow a bit of growth to have a finished height of 6'. Would also like to trim the side faces quite hard to reduce the overall width.
Before I start can I just get some input if the hedge is likely to withstand such a drastic pruning as don't want to be left with just a line of dead stumps! Don't know if it makes a difference but the trunks are about 4-6" in diameter at the height I'd be cutting and I'll likely just use the chainsaw. If I can go ahead is there a best time of year to do it?
Thanks

 

Hi

its best done over 3 years ... its nesting season so check for nests ... most of us would want your hedge

• Year 1 reduce the height
• Year 2 reduce one side (only)
• Year 3 reduce the other side

after that its just a trim nothing else

you will need to feed and water during the summer .. if you cut it all down in one fell swoop it may die in places and doing it my way will still give you privacy.

Spruce

 

Having had holly in the past I'd get rid of it entirely.
But that is just my opinion.

 

A couple of deer would work. I'm about to dig my two out as they've badly pruned them.

 

Best time to do it? Later on in the year after the birds have left their nests.