They are hard to find, but we still grow the traditional giant tom turkeys, the ones that weight over 30 and sometimes 40 lbs in size.
Giant Tom Turkeys will feed an extended family gathering of 10-15 adults with one oven and one cooking session. As a bonus, larger birds have more breast overall, so you will get a higher ratio of white meat to share around. For reference, a 25 lbs turkey will yield about 20 servings + leftovers, or two helpings for 10 adults and some sandwiches for the next day.
Cooking times are longer because the Tom Turkey is bigger, but it's less hassle than cooking two birds back-to-back in the havoc of Thanksgiving dinner preparations. All the same cooking tips for Liberty Turkeys still apply.