If you look very closely, you will find that the exterior dimensions of this house are 18'x25'--a gross area of around 450 s.f. In real estate terms, it is a two bedroom dwelling, but there are some minor code violations that would render its construction a bit difficult. In terms of suitability for living, it would please many people--provided the family size was relatively small.
I'm worried that the small dwelling phenomenon is garnering too much attention. The desire that people express for 3 and 4 bedroom houses with lots of space is a real thing and dominates residential construction. The focus on the Sun Belt as the stylistic and cultural is reasonable when we consider that most construction starts are in that region.
The nuances and characteristics of the New England vernacular are losing their portability. Why put a Cape on a lot in Texas?