In a large Dutch oven or slow cooker, combine the frozen diced hashbrowns, chicken broth, diced onion, minced garlic, seasoned salt, black pepper, and half of the crumbled bacon.
Stovetop: Bring to a boil, cover, and simmer on medium-low for 20 minutes until potatoes are tender. (Crockpot: Cook on LOW for 4-5 hours or HIGH for 2.5-3 hours.)
Reduce heat to low and stir in the softened cream cheese cubes and 1.5 cups of shredded cheddar cheese until completely melted and velvety.
Lightly mash a few potatoes against the side of the pot to naturally thicken the soup.
Serve hot topped with the remaining crispy bacon, cheddar cheese, sour cream, and sliced green onions.