Hi Jim, i've done all-sky brightness checks of various places on Exmoor, the last one I did was after the first lockdown but before this current one (so reasonably current). As a general rule of thumb for Exmoor the darkest views right down to the horizon are to be had to looking to the South and West (this is assuming you don't have any localised light pollution problems near you within the park). Everywhere else don't expect any miracles below about 15degrees altitude, especially from the North West round to the East where there is a pretty much solid and continuous light curtain of white and yellow light (from various origins). For Exmoor's case specifically it is such a small and light-vulnerable national park that zenithal sky brightness (often quoted on light pollution websites and dark-sky associations) is not representative of what you see as a visitor/resident. Let me know if you need any more info, I probably can give you a more definitive answer if you want to pm me your location. Kind Regards.