So, where to secure a location. At this juncture, your best bet for a hold out in my opinion is;
Scotland - The rugged Highlands. Just above Fort Augustus there are a myriad of smaller lochs with a number of small hamlets. Building out in these areas can prove difficult however with a moderate budget it is feasable if you cannot find available locations. The best advice I can give is to seek somewhere with an exceedingly small population with very limited external connections. It will make some purchases and logistics strenous but the payoff is isolation in which you can operate as you wish. There is many a nook and cranny a cunning man could live and even build anew within. Knowing Gaelic can be a bonus the further north you go as it's more prominent (as it should be) but it is not an overt requirement. One thing of note I would add is thanks to media, many Scots when they hear of an American who has Scottish heritage may roll their eyes. This is mainly due to the deluge of "comedians" who the parasite has employed to ensure no brotherhood can be formed (the same is employed to ensure division among internal groups in Britain as well, such as north and south of England etc). Americans as an example are presented by Scottish comedians as "fat and lacking culture so they come to take ours" along side usual caricatures of a fat man wearing a Haiwain shirt with a fanny pack and a camera. The key to counter is simply to act and present yourself in a respectful way (but I think anyone reading this already understands such things, this is merely for anyone passing by wondering the situation).
Wales - Wales is a sad story. Many of it's once proud and welcoming villages lay precariously between poverty and ruin. However it is in the more northern and northwestern coastal regions one may find a pocket with some life left in it to make a stand, the coast by Snowdonia is most beautiful also, a man could find peace there. As an Englishman I have always had a budding respect for those I would call brother and the tale of what was done to Wales by a country who should of been it's kin is a shame that weighs heavy. They are a noble people we abandoned and a very proud people still. If anyone does wish to move there I would advise learning Welsh both as a sign of respect and for sheer utility. I know the respect part is not really needed to be added but it's just for those unaware of the importance of their language to them and for awareness of avoiding insult to anyone unfamiliar. It is used quite widely in street signs and general conversation and is quite a pleasent language to know.