Dropping one's trailer in an unauthorized space or somewhere like a truck stop or hotel where other potential customers can't park is against the law in some cases and unprofessional at the very least.
When I ride around my hometown on the weekends, I see trailers dropped at the local Pilot truck stop and at motels. From there, the drivers unhook and bobtail home, thereby taking away a much needed parking space for a paying customer and someone struggling to find a place to take their 10 hour break. We all know parking is tight, especially in the more populated parts of the country. If you travel around I-495 
north of D.C, you'll see dropped trailers right there on the interstate shoulder on the Maryland side. UNBELIEVABLE!
No one promised us free parking for our trucks and trailers when we go home. If you have plenty of room on your own land and it doesn't violate any rules or regulations in your community, go for it! If not, I recommend that you find a safe, spacious lot and get permission to either park your entire rig or to drop your trailer and bobtail home. I pay for a parking spot that's located at a construction company near my home and is conveniently located beside a U.S. highway. The lot is secure and watched often as the owner lives next door. I never have to worry about a parking spot and I don't have to worry about someone stealing from me. The nominal fee for the parking is well worth the peace of mind.