If you want real cool-climate from Napa, you need to be Oak Knoll or Coombsville or Atlas Peak. Also the eastern part of Conn Valley closest to Lake Hennessey. Maybe Yountville in a non-hot year. Don’t confuse old school winemaking with cool climate. One is not the other. Corison is old school, not cool climate.
Several good alternatives have been mentioned here already. I will add a few that fit the cool climate definition for Napa… Stone The Crows, Fairchild “Sigaro”, William & Mary Cabernet and Red Blend wines, anything from Moulds Vineyard, anything from Farella Vineyard, anything from Caldwell Vineyard. Also Meteor, Faust and Bond “Melbury.”
Of course, “cool climate” is all relative in Napa. Coombsville is still warmer than anyplace in Bordeaux in most vintages. One unusual (but sometimes excellent) cool climate Cab would be Dehlinger Cabernet Sauvignon Russian River Valley. At least by Napa definitions.