Thanks Jon for posting this. I'm sure it would certainly help. It's a bit expensive from what I see. I have found that using an old carpet does a great job insulating the tree. I also put a tarp in top of the carpet. It had worked great for years.
There's as many methods as there are fig growers in the cold climate. Many of us found a way that they're comfortable with.
I visited an farmer with Bill in NJ last year who swears by his method. He built what looks like an old phone booth with glass. He puts it over the tree and fills it up with shipping peanuts.