Q: Can a mature blue spruce be transplanted?
If the tree is quite large, you might consider hiring a company that has a tree spade (a large piece of equipment designed specifically to dig and transport a tree in one simple operation).
It may be a larger job than you want to tackle on your own, plus the rate of success would be higher if you hire a professional.
The tree will require care afterward, so be sure to arrange for this to maximize its chance to survive.