On our Rushmore, the factory scheduled the build and the dealer received a confirmation of the order, showing the content, several weeks in advance of the actual build - in our case it was only a few days after the order was processed.
If I remember correctly from the factory tour, once the frame assembly hits the line, a Bighorn is built in about 1 1/2 days.
If you ordered more than a few days ago, the dealer should be able to provide a copy of the build confirmation, including the VIN #, and a planned build date. If they aren't sure about the build date, but get you the VIN #, a call to Heartland can also probably get you the planned build date.
If you ordered at an RV show, there could be a few days lost because the dealer is submitting a large group of orders all at once.
If you ordered 1/2 or full body paint, there's additional time at the paint shop after the unit is built. I think the most unpredictable part of the process is how long it takes before a driver is available to deliver it. Winter weather also sometimes creates delays.
Anticipatory excitement is just part of getting a new RV. You've ordered and fun is around the corner. It won't be long now.