Cloth of any decent quality is not hard to alter to fit, often clothes were made with extra material with the expectation of being altered likely multiple times to fit different people.
Also people did't really buy cow feed at the time, they were grazed on nearby fieldgrass in the summer and fed harvested hay grasses from their own fields in the winter. And it doesn't take all that much work to use a scythe to cut literal tons of grasses. With just a minimum of practice you can cut 2-3 acres of grass a day without straining yourself, provided you are fit, which any pre-modern farmer would be.
The article says clothing was passed down generations.
> Because clothing was often tailor-made rather than ready-to-wear
What if the father's clothes don't fit the son? Now you have to choose between feeding your cows and buying a shirt.