I'm sorry, but using data from US averages (largely representative of single-family-home suburbs) to make sweeping statements about how urban living is bad is simply misleading and borderline irresponsible. Living in a multi-family building, living without a car, getting electricity from renewables, and using electricity for heating and cooking is insanely energy efficient. It takes advantage of density to reduce infrastructure needs, and can benefit from having resources developed / farmed at scale, further reducing energy and emissions.

If you need ANY infrastructure to connect your "shire" to anywhere else, you need to include that in your analysis. It will have a massive impact. Need a car? You've already lost. The road infrastructure per capita alone will put you over the edge, let alone the infrastructure required to build and maintain said car or the emissions from the car itself if not electric.