Easiest route to the redwoods from the north with trailer

They are all twisty and windy. But they all have semi's traveling them every day so you will be fine on any of them. You can certainly go over from Portland or Salem and have the least windy roads but you will be a long time going down 101 that far as it will be very slow. You will also see the most beautiful scenery in the world--OR on 101 going south is spectacular.