The locations in the Christmas Where Was I?s are quite often, as in this one, spread across Britain so each is not necessarily related to the others. Conversely the locations do not help to confirm one another as they do in the weekly puzzles. Basically, don't worry that there appears to be no connection!
Is Brown Willy the mountain or the king? ;-)
Either way, I don't think you are right: look further north for the mountain, which is a significant deviation from the path implied by the other locations.