Thanks everyone for the tips!! You all have confirmed my suspicion that biking north along the coast is a recipe for frustration. I remember biking from Berkeley to Davis, CA last summer and cursing for at least 1 hour solid as the wind is relentless north of the Carquinez straight...that was not very fun and biking all the way to Seattle with a howling headwind sounds nasty.

Maybe if I ever want to bike north on the coast I'll try riding north in the winter, as fiestsbob suggested.

We're pretty set on biking to Seattle this summer, so it looks like we have many options to explore! I-5 would take us through Eugene and Ashland, which are places I would like to check out, however I associate I-5 with semi-trucks and cars going 90mph, but maybe it's different farther north. At least I hope so! Staying east of the Cascades looks good too; clearly I have a lot to research! Thanks everyone for the route ideas and all the responses to my very first post!