Place frozen hash browns, cream of celery soup, broth, ranch packet, and 1/2 cup bacon bits in the slow cooker. Stir to combine. Cook on Low for 4 hours.
Remove lid and mash potatoes to desired consistency (or leave them whole for a thinner chowder). Add cream cheese. Cover and cook for 1 hour more. Season with salt and pepper.
Ladle into bowls and garnish with cheese, green onions, and remaining bacon bits.