Look at it from this stand point. You got a great story to tell.
Haven't used it but Garmins 760 RV LMT is supposed to be able to handle things like that.
We just go for the story. Ours: Looking for Fools Hollow, USFS CG, in Showlow AZ. GPS put us on a dead end road. Turned the trailer around and kept looking for the CG. Turned out to be run by the State Parks.