Slow Cooker Loaded Potato Soup

to 3 1/2 lbs russet potatoes (, peeled and diced into 1/2-inch to 3/4-inch pieces (about 7 medium potatoes, 8 - 9 cups))

medium yellow onion (, finely diced (1 cup))

low-sodium chicken broth

evaporated milk

Salt and freshly ground black pepper (, to taste)

butter

all-purpose flour

sour cream

shredded cheddar cheese ((6 oz))

bacon (, cooked and diced or crumbled)

green onions (, diced)