In Texas I don't remember ever doing a century without chip seal, we love it here for paving. But fresh chip seal is another problem! Those little chips stick to your tires and are way rougher. If you can't re-route funny signs will at least make the ride memorable. I have had rides where they comically announce water over the road ("We filled the low water crossings just for the ride") or rough roads ("They didn't realize we weren't hosting cyclocross") or a controlled burn ("In case you don't get hot enough the forest service built a fire for you on the route"). I just giggled each time when I got to those sections. People will complain but some for a lot of people a little humor goes a long way.