In a small bowl add yeast, sugar and warm water, Allow to proof until light and foamy, about 10-15 minutes.
Place instant mashed potatoes in a small bowl, heat the milk and butter in microwave until milk is hot and butter is melted, but not boiling. Pour the hot milk over potatoes and stir gently until combined.
In large mixing bowl with dough hook, add the salt and 4 cups flour, stir gently to combine. Add the yeast mixture and the mashed potatoes to the flour and continue to mix. Gradually add the rest of the flour until it is no longer sticky and wet(you may not need all 7 cups, depending on the humidity). Knead the dough on the #1 or #2 setting of your mixer for 8-10 minutes or until the dough begins to pull away and cleans the sides of the bowl. Remove dough and place in a lightly oiled bowl, cover and allow to rise until doubled in size. After dough has doubled, punch dough down, divide in half and form into 2 loaves, pressing out any air bubbles that may have accumulated during rising.
Place in two (2) 9x5 loaf pans and allow to rise until about 1" above the top of pans, usually about 45-60 minutes. Brush tops gently with butter or olive oil. Bake at 375* in middle rack of oven for 20-30 minutes. Inside temp should be between 180* and 200*. Let set in pans for 5-10 minutes then remove to cooling rack. Allow bread to completely cool before slicing (eliminates a crumbly texture).