dice the celery, carrot and onion (if you have a small food chopper it makes this much easier).
cut bacon in small bite sized pieces and pan fry until done but not crisp. Save 1 tablespoon of drippings.
using a large dutch oven melt the butter and add the tablespoon of bacon drippings.
saute' the onion, celery and carrots, garlic, pepper in the margarine until softened.
add the diced potatoes with the water and chicken broth along with both packages of au gratin potatoes both the potatoes and the sauce packages. make sure all the potatoes and vegetables are covered with fluid (water and chicken broth). Add most of the browned bacon keeping some out to garnish the top of each individual bowl.
If you need to add more liquid add equal parts chicken broth and water.
boil on medium high heat for 40 minutes or until all potatoes are softened.
Watch your liquid. It evaporates quickly. Add equal parts water and chicken broth. If you have to add liquid add 1/2 cup broth 1/2 cup water to start and keep adding liquid in this fashion. A lot depends on your altitude. Just keep a close eye on it.
take a potato masher or fork and coarsely mash the potatoes and vegetables leaving lots of chunks.
add the pint of cream and heat throughly being careful not to scorch the soup.
heat on low until desired consistency. It thickens up quickly. Dish into bowls and top with green onions (scallions) and bacon.