Hello!  Happy to help.

Unfortunately your Colorado blue spruces are really not suited to Minnesota weather and soil conditions.  They are very susceptible to two chief diseases that make them look deplorable but takes years before they succumb if at all.  The two diseases are Rhizosphaera needle cast and Cytospora canker.

It's more likely your trees are affected by Rhizosphaera needle cast which is a fungal disease and, yes, treatment for the fungus can be tried but it's complicated by the fact that you need to identify the fungus with a lab test so that the correct fungicide is applied.  As your tree and shrub people noted, the trees are difficult to treat because of their size.

We're now recommending more resistant trees with a blue cast for residences such as the concolor fir (or white fir).  Here is a link to wonderful information about choosing evergreens for your landscape from the U of MN Extension.

I hope this information helps.

So where can we find the lab to test them? Where to find ppl to apply the treatment? Will they spread to other evergreens? 

Hello.

For testing send a symptomatic twig to the U of MN Extension Plant Disease Clinic.  Here is their link.  Contact them first to learn what type of specimen they'll need - it'll save a lot of time.

Here is information about how to find and hire a certified arborist to help you with all things trees.  They can make recommendations for people who can apply the correct fungicide if they're not able to.

Please know that your trees will live a long time with the problem.  They just won't look very good.  I have two such trees on my property that were there 24 years ago when I bought the place.  They're still alive but I can't justify taking them down.  Some people limb them up as the lower branches start looking bad.  

The fungus comes in on the wind so even if you take down the diseased trees, other Colorado blue spruces can contract it.  

Trees need a lot of room for their roots so planting new trees nearby may be problematic due to competition.  Also once the roots extend under roads and sidewalks, their ability to take up moisture is reduced so they should be set way back.  I've included a diagram of how far tree roots spread below the soil.  You'll notice that they're shallow with respect to the height of the tree but the huge spread balances the bulk of the tree above ground.

I hope this helps.