It's the triple rig that make you a target for cops. Truck, RV, plus something being towed behind the RV. People have been doing this for years with no problem. Well RVs keep getting bigger and longer soooooo, you may be over max lengh now.
Go ask a commercial DOT cop what would happen to an RV if it got pulled over and was found to be too long. The commercial cops would know. Find them at your favorite truck stop or if you are feeling brave, go into an active weigh scale on the freeway. You may even get lucky and find a in the know officer at a public rest stop.
Here is the 2011 guide per state from Woodalls.
2011 Driving Laws for the US and Canada