I have a 65 qt Whynter in use as a fridge and by the time I pack it with fresh veggies (salad stuff and some for cooking), a 1/2 gal of juice, qt of milk, 1/2gal of water on chill, various condiments and cheeses, and a dozen eggs, it is FULL.
I also have a matching unit that is set at freezer temperature which is packed with meat, frozen veggies and bread type items. As a single person I found that shopping for meat was the worst situation without the freezer as I was forced to either shop at the butcher counter for one of each or buy a counter package and eat, say, chicken forseveral nights in a row. Having the freezer means that I can buy a family pack, usually at a discount, and have my choice of meats. I single pack meat as I buy it and then freeze it.
I generally shop once a week because I need fresh produce.