Winter doesn't bring too much extra cost as long as the home doesn't have outdated appliances and has sufficient insulation.

The problems with the project mostly stemmed from the crawl space work, which required shoring, replacing structural members, leveling floors and insulation. 

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Sounds like if you know and follow the rules you should not only be OK but pretty well insulated from competition (people swarming in and oversaturating)

You still have flooring, cabinets, bathrooms, plumbing, insulation, paint, etc, so all that cost remains the same it would seem. 

Quote from @Blake Van Ness: Hello i'm working Insulating my garage.

The build cost would be a little higher because i would use foam in the exterior walls and also use insulation in the interior walls for energy saving and sound dampining.

Doors, windows, and insulation installed. 

I make sure they're well insulated, have replacement windows, spend more on nice flooring that looks great (plank style / wood-look porcelain tile, hardwood or click-together LVT planks, not peel-and-stick squares). 

You are correct that insulation is almost certainly a bigger bang for the buck in a heating climate.