I will disagree on this method of keeping then in runs, horses should be stable in open pastures with wind breaks. Not kept in some "run/paddock/small turn out area" either by their self or a number of other horses. A horse needs some space. Have not clue what a track is or how large, never heard the term.
As to the going away/Fad issue? Not so much: Think on it - less shoveling of manure and stable chores, lower cost of operation in that sense... and the very wealthy can have a feel good and impeccably trained horse as a result... Small acreage large number of horses will produce a manure problem. Will produce health problems, will produce injury problems. Even now many townships have rules and regulations on manure handling for a horse operation, required amount of space for each horse, etc.
Science is proving that round pen training can cause problems with bone development in joints of horses as well as mental problems caused by this type of training method.
There will be a short list of highly succesful operators of this nature. Kind of like the top racing stables - those who do what they do the best will thrive even in tough times. The rest will have overimproved properties which will go begging when they deep-six on feed costs. Agreed and there are currently a lot of then all over the country that have gone belly up. Many are supported by other income.
Gatlin -
You probably want to Google for ALL the 'natural horsemanship' type gurus. This actually may be a REAL wide range for possible similar properties - even international! Correct. You might try the National Horse Council, State Horse Councils, Breed Associations, National and International Shows, such as the American Royal, Denver Western, Ft. Worth Fat Stock Show and others. They should have mailing list of commercial stables in there area. But be sure and check how they are supported.
You may want to ask who (if anyone) else has built something like this: Dennis Reis, Clinton Anderson (Aussie), Buck Brannaman, Mark Rashid, Monty Roberts, Ray Hunt, Steve Jefferys, Pat Parelli are good places to start... Some of those guys are mostly retired, but would know who's who and where they are! There are about 8 who are highly prominant - most have more traditional stabling arrangements. Most of them also operate in climates of less extreme nature than WI - and have stalls/runs and more traditional stabling facilities... Most had incomes other then the boarding and training that there operation depended on for income. Sponsorship from different manufacturing business, Sale of books, videos, production of clinics nationally. Even today if you visit a number of equine web forums you will see these "top trainers" tickets to there events being given away for people to come. Its all in the marketing and sponsorships to make money on sales.
Each of the names listed above have and use different methods for training. With Ray Hunt being about the basic and the best, I feel. There were many before him, who just did there jobs on the ranches as head wrangles. Even today it is said for every one that seem to become popular for a one to five years, there are 20 more working on the ranches and horse remuda's that are just as good or better. The others went on to expound off his theories. Some I feel from an old horsemen’s and cattlemen’s view is just plain BS. “Carrot Sticks”, “Special Lead Ropes that you wiggle like a snake”, “voodoo juice”, special bonnets for your horses head the list is endless of the gizmos that some of these people sell to their followers.
You are also looking at a cross section of some 50 years for these names, that is a lot of years to divided then into and then divide then across N. America.
Not sure of the advisability of chasing the 'cost to cure' for installation of stalls etc... as there will be a LOT of those facilities available as existing stable operators go belly up . There are always a LOT of those in tough times as horses are a pretty expensive hobby - similar to if not exceeding boats as holes you throw money into. Discretionary funds activities get cut deep when times get tough. Lots for sale in Wisconsin and lot more across the country. Most are turned into some type of storage business. These places come and go every year.
However you won't have as much physical depreciation (superadequacy) in what you describe and the facility may have alternate H&BU depending on location... like a really cheap place to park SUV's and Motor homes which only get used once every three years or so - can't be sold for near what the owners have in em and are too pricy to store someplace else!
Please keep me apprised of your progress, we are seeing more facilities edging that way down here...