This breed carries a 4-out-of-5 energy rating and a documented Energetic temperament. That is genuinely useful information in Anchorage, because it gives you a baseline that a lower-drive dog would not. A Welsh Springer that stops asking for the walk is telling you something. The trouble is that Anchorage supplies a ready explanation for it eleven times over: it is dark, it is minus ten, the trail is ice, nobody wants to go out.
The practical answer is to make the observation numerical rather than impressionistic. Weigh the dog on the same scale every month rather than judging by eye through a winter coat, and note when the daily walk starts getting shorter by the dog's choice instead of yours. A thyroid panel is a modest, ordinary blood draw. Alaska's cost of living inflates it, but not to the point where an annual baseline is unreasonable — and having last February's number to compare against is what turns a vague sense of slowing down into a decision.