The newest homes that FLW had a hand in building date from 1959.
By the standards of the time, they were comfortable (if a bit lacking in closet space).
If you'd like, you can buy a modernized kit Usonian (inspired by the Jacobs I house) from Lindal here:
Looks more MCM than FLW to me
That hous is still extremely small for what most people in the US would put in a full sized suburban lot: Nowadays a median build is 2300 square feet (213 square meters). It makes that 1600 square feet look very small. The hallways, the large space dedicated to a great room and just 2 bedrooms won't help.
You will find new houses that small, but typically when it's extremely high value land, so typically infill. And then chances are it's a multi story house that fits the lot to the limit.