Unless you really want the one you ordered because of color or whatever, do a search on Autotrader or where ever. There are plenty advertised.
Many on Autotrader will deliver a brand new one to you. Just to F&^* with your dealer, I'd tell them you want it for $2000 off MSRP. If you're cancelling, what do you have to lose? Hell, make it $10,000 under MSRP, then maybe meet at $2000 under MSRP.
If they say no, from the ADM dealership, and in front of the salesman, call the advertising dealer, and tell them you're on your way to buy. (Might want to call the advertising dealer before going to your dealer just to make sure it is available and it is priced as advertised first.)
The dealer knows what has happened to demand in the past month, and is hoping some fool is still willing to pay an ADM in this market. If he doesn't, he can advertise it all day long at with the ADM and it will just sit on his lot.