Lightly grease slow cooker with nonstick cooking spray.
Add diced potatoes, onions, carrots, celery, garlic, 2 strips crumbled bacon, 4 cups chicken broth and all seasonings and spices. Cook on HIGH for 4 -5 hours or on LOW for 8-10 hours or until potatoes are completely tender.
Remove 1/2 up to 2/3 of the soup (vegetables and liquid) to blender along with cornstarch, 1/2 cup evaporated milk and cream cheese. Blend until very smooth, being careful to let smoke escape or it will explode (I leave a corner open and cover with a paper towel). If you need more liquid in order for your blender to blend, then add additional evaporated milk.
Pour creamy blender contents back into slow cooker along with remaining evaporated milk and stir to combine. Cook on HIGH for 20 minutes then stir in 1 cup cheddar until smooth. For a thinner soup, stir in additional chicken broth.
Garnish individual bowls with additional cheese, bacon and plenty of green onions.