Dogs that originated in the northern latitudes grow an 'undercoat' that is somewhat similar to cotton or down and this gives a lot of insulation.
The ability to grow this kind of fur is genetic, but the amount and thickness is heavily dependant on the gradual exposure to cold a dog gets if it is living outside as the seasons change.
A dog kept outside during the day and inside during the night may not grow his undercoat very well because 'inside' is kept at a reasonable level so it fells like a warm spring day (or warm spring night I guess)
A dog that stays outside year-round in Minnesota will be able to handle the cold as long has he has a decent dog-house to go into (small enough so he can warm it with body temperature, insulated, flap or something to keep the wind out. When it gets -20 (not counting windchill) the outside dog just spends most of his time in the doghouse, when it is 10 above, he's outside just fine. That won't be true of a dog that is spending nights indoors. Oh sure, when you go out to shovel the sidewalk or go for a brisk walk for a few hours they'll be fine, but during our coldest days, a dog that is outside from 7am to 7pm is going to be out in too cold of weather for too long for an underdeveloped undercoat.
It's really more of an all or nothing thing. Either have him be an inside dog that can still go out in the cold for hours but not all day...or have him be an outside dog.
I am guessing the underlying issue is you don't want a dog free-roaming in your home while you are at work. Look into crate training, getting a dog walker to break an 8 or 9 hour span into two smaller periods, or look at the training and relationship building that you'd need to have a dog that can be in the house even when you are at work and be non-destructive.