I am sure there are many folks with this kind of ideal, but the obstacles are significant.
Going back to my earlier comments, new development in rural areas is almost invariably against local policy - driven by the fact that it is against central Government policy.
The 'reserve' idea is not relevant really in terms of assisting or hindering any application for a residential dwelling. New agricultural dwellings have been built by a few landowners but they will need to be linked to a clear business plan that shows that the agricultural venture is a viable business - mushroom farming, market gardening - you name it, it has been tried.
A new farm/forestry worker's dwelling may also be possible when applied for by a farmer who can demonstrate aneed for a person to be around 24/7 to tend animals.
This doesn't sound like what you have in mind.
I am sure that you can appreciate that the pressure to 'defeat the system designed to protect the rural landscape' is immense. Any application believes it should be a special case. It has been done but the exceptions are few compared to the applications.
Good luck in your learning about this.