Be careful on those roads. Tires won't be your biggest risk factor... it will be speeders and impatient drivers. We are at a real disadvantage on these sub-300lb dirt bikes.
I think the best reason to drop a few teeth on the rear is to get the rpm down when you are driving on the highway. Personally, I am not a fan of going faster on a dirt bike, but having a less buzzy, lower rpm for long distances is more enjoyable.
