No, you do not need to rip out the vines or cut them back severely. Pinot noir vines and other European grapevine (Vitis vinifera) will have grape powdery mildew infections if they are not sprayed with preventative fungicides. The fruit should be cut off the vine and dropped to the vineyard floor, and the canopy can be saved by spraying it down with water. Water helps kill the current spore population. You can follow it with a horticultural oil application. To learn more about this, I suggest that you read the article:
How to deal with a vineyard powdery mildew outbreak

Then, you should plan a powdery mildew spray program for the rest of this year and the next growing season to avoid this happening again. You can find details on what to spray for powdery mildew in the Pest Management Guide for Wine Grapes in Oregon.