I have several Salvias - Salvia greggii 'Pink Preference' which is listed hardy to zone 6, Salvia X 'Maraschino', likewise zone 6 and Salvia greggii 'White Wedding' which is listed to zone 5b. I have no idea if they will survive the winter here. I am in zone 6, not sure if it's a or b since the zone lines tighten up near the coast. Since Salvias are one of my favorite plants I thought it was worth trying.
Salvias in my experience are not one of the top butterfly attractors. In my current yard I have several other good plants nearby. I carefully checked my asters and buddleia for other moths but saw nothing.
It's good to know I'm not the only one appreciating the Salvias in my yard.
Now if my Salvia elegans (pineapple sage) will just manage to bloom before it dies back for the winter...