Stick with the “general use” tyres for North Wales. Even in the depth of winter its the tyre compound you want to look for rather than the tyre tread as its never that muddy, just wet.
Trail king, high roller, that sort of thing.
The ardent will probably be okay as long as its a softer compound. It doesn’t need to grip into loam or mud, just went rocks at Penmachno and CYB. Dyfi forest is a tad muddier! Take both!