Going North on 101 From Tillamook Need Advice Where 2 Stay

I just tried several campgrounds from cannon beach north to above Seaside and was told that this coming weekend is the Hood to the Shore relay race and that there are very few sites available up there. We're in friends, cancellation, and will be going back to Pacific City tuesday, another cancellation, and then to McMinnville for the weekend, still another cancellation. Been pretty lucky as all our stays were possible because of cancellations.