I looked on the internet for auto glass replacement in my area at the time (Sacramento), and found 1 company that included "RV's" in their list of types of vehicles serviced. They came out to my storage space, measured my broken lower pane, went back to their shop and fabricated a replacement smoke safety glass pane. They came back to my storage lot, and were even able to install the replacement pane without removing the window frame.
Have you called Heartland Service with your VIN number at the ready?