Thank you very much to everyone that has posted, I really appreciate the advice.
There are very many similarities between Wales and NW Devon in terms of influx into a rural environment, exacerbated by the 'mad Covid' period.
And there are many pros including that property prices are marginally cheaper, there is more cheaper 'upland' farm land available, DS's (and my) livestock, rural skills and willingness to adapt to the local environment/culture would be welcomed (mostly) and crucially that Welsh Planning Regs, allow for the establishment of new 'homesteads' as long as it's for the genuine purposes of sustainable agriculture.
The Cons are the other facts - although I'm currently 61, fit (but ungroomed) and not able to retire until I'm 67, and wishing to move property in 2 years (currently priced into town-living but with too much house and not enough outdoor space), a fit 63 year old could (and eventually will) turn into a less-fit, possibly burdensome, person sooner rather than later. Rather like the retirees that having been doing similar in recent decades.
DS does currently require some additional support with organizing and sustaining his existence and doesn't much like change but inevitably he will be without me and I know that 'rural' communities do look after those they regard as their 'own'. So I would be UR to move to the Welsh uplands to start our own farming enterprise, then pop my clogs and leave DS on his own before we get properly started, to specifically answer @Kangaroobrain
So, my current 'strategy' is: Plan A stay put in the area (and hope), Plan B keep considering Wales and Plan X - what actually happens after life does it's stuff.
Diolch i bawb.