For those unaware, RDR2 is a video game set in the last days of the old west from 1899 to 1907(ish). The setting is a somewhat condensed region approximately covering Texas and the states around it.
Additionally, the catalogue, by description of the in-game retailer, apparently had multiple models of pre-cut home that were implied to be somewhat customisable. How realistic is this?
So this is 100% based on Sears Houses which could be ordered out from Sears Catalogs "back in the day."
http://www.searsarchives.com/homes/1908-1914.htm
You can see several models here.
Many of the "stereotypical farm houses" that Americans recognize as such were actually Sears houses. Those houses were not original homesteader houses, but usually 1900s-1930s houses that were built later when farming families started to make more money (esp during the 1920s). They could also be found in urban areas as well, but the "farmhouse" is probably the most recognized style even if it's not recognized as an original Sears house.
https://www.npr.org/2018/10/20/657770791/sears-is-fading-but-memories-of-its-mail-order-homes-endure
The houses were not only the blueprints, but also mortgages and all of the materials including cabinets, garages, lights, and so on. Kind of like if Ikea were sell complete houses for their customers to build. These were almost the prototypical cookie cutter houses with many original owners buying the same models in the same areas.
Not only are many of them being better preserved, but they've become collectibles in their own right with new house owners actively trying to buy new ones as they come on the market. Some houses go for a lot of money- far more than neighboring houses.
Even the catalogs and extraneous items associated with Sears homes have become collectible as well.
The houses lost popularity and ended in 1940 with the advent of WW2 due to the loss of materials, taste in architectural styles, and the start of suburbs with the post WW2 mass housing boom.