Nice graphic! :)
I've been to sites like that, but not where I couldn't level it.. The tongue was so low, I had to use a single 2x board for the jack. I normally use 2 4x boards stacked on top of each other!
About the only thing you could do is put enough boards under both sets of tires to get the thing up in the air higher so there is more room for the tongue to go lower.. Not very practical I know, but sites that are built to hold an RV "should" be made as level as possible when the pad is laid! ;)
Anyway, good luck next time!
Mitch