can't even begin to answer this question, but a long time for sure. To begin, we have over 400 pounds of fresh irish potatoes, sweet potatoes, butternut squash and Long Island Cheese squash in the basement, and a 50 acre woodlot if no other source of fuel was available. And 50 acres of trees would be over a 10 lifetime supply of firewood. If freezers were available, then we have a couple hundred pounds of meat plus assorted vegetables, fruits, cheeses, nuts, flour and soups and stocks. In the pantry is over 50 pounds of oats, 81 quarts of potatoes (recently canned them), 100 quarts of tomatoes, green beans, corn and peaches, plus 50 pints of raspberry jam and apple sauce. The first item I would really miss is the whole wheat hard flour, only have 15 pounds on hand. But I think I have 40 pounds of ww soft flour in one freezer, so would have to switch from bread to pancakes and biscuits. In the garden we still have celery (but the cold snap is arriving today so will drag out the bed clothes again) spinach, kale, carrots and lotsa parsley. And the garlic crop is in. Think we would last quite a while.