John, I agree that is a very nice set up to protect the tree. In fact it's the best one I have ever seen.
Although I'm not as far north as you, it gets pretty cold here in our part of Connecticut. In fact it got down to minus 11 degrees Fahrenheit three winter ago. It seems to me that what your planning on doing should protect your tree, very well.
I'm assuming the reason why you are rescuing the tree is because of it's taste?
Can you describe the taste? Is it a fruity taste like Marseilles Black VS. Or a figgy taste like Hardy Chicago. Or a very sweet taste like white Trianna?
Thanks.
Bob