If you have a food saver, and vacuum your cold smoked salmon, it will be OK in the fridge for about a month. YOu can keep it longer in the freezer, but since it is a very fat fish, use it before six months. It is wise to freeze cold smoked salmon, as it is raw, and it will kill Listeria monocytogenes.
There is little or no flavor or structure damage on the frozen fish. In fact, I think the flavor from the smoke develops if you freeze the fish for a week or two. When you cold smoke your salmon at home, the smoke flavor can be a bit bitter and overwhelming when it is fresh. The smoke taste mellows and develops during the storage.
Do not store cold smoked salmon outside of the fridge. Cold smoked salmon, not vacuumed, can be stored for about a week in the fridge.
As an example, unsmoked salmon can be stored for 18 days at 0 degrees C, but just 9 days at 5 degrees C. Fish is very temperature sensitive.