I see tandem rigs all the time here in Michigan. Usually it's a truck + 5r + boat, but more often I've been seeing Class A + truck + trailer.
Last weekend I stood witness to someone that had to "bring all the toys" with them to the campground. Massive class A DP towing a f350 dualy truck carrying two jet-skis on some sort of rack on the bed, towing a triple axle cargo trailer. He was trying to fit into the driveway of the little campground up the block from my house. Everyone was scrambling to move their vehicles and boats out of the way.