At long last!
Unlike others above, I'd be OK leaving it at the dealership if you trust them and expect this will "give you +++++ brownie points" for your next purchase(s) since they'll likely get ++ PR displaying it in their dealership. And maybe (?) they'll throw in free PPF as an extra bonus for you leaving it with them. BUT:
-make sure you've got an understanding (in writing) of how they'll look after the car and that it'll be covered by their insurance. Plus your name goes on their insurance for the vehicle, as an additional insured IF you've paid for it or a good chunk of it (see below);
-it should be parked locked with the top/windows up, and cordoned off so no one is able to touch it which means NO ONE can sit in it or play with it;
-the battery should be removed...or at least it's kept on a battery tender however that may make it too tempting to do things with it, if it remains powered up;
-you're contacted before it's ever moved, so you're kept informed and know what's happening with it, at all times (ie. they may need to move it, depending upon what's happening in their showroom);
-are you expected to pay for it upfront...or only with "actual delivery" in the Spring? When will the warranty start?
Some food for thought, but the main thing is that it'll soon be at your dealership! Congrats!
PS: I'll let others chime in and point out why leaving it at your dealership, even under the above conditions, isn't a good idea...