Considering Crawford State Park and Roaring River are only three hours apart, and on the eastern edge of Kansas, I would suggest Twin Bridges State Park in eastern Oklahoma as an intermediate destination. The state parks keep campgrounds open year round (COEs are seasonal here) and it is less far off your route. If you really want to spend some time at Copan Lake, I recommend Washington Cove, because if Oklahoma 10 is still closed at the Copan Lake dam, you will need another 50-60 miles round trip to get to the Post Oak campground on US or state highways.