I know exactly what you mean regarding the height of the caravan, caravans used to be just slightly lower and mine is exactly the same and I have the same problem, it's not the legs that are too long its the material of the awning, I get round this problem quite easily by putting the caravan on a wooden block, it's only a couple of inches too long so just raise the caravan on a couple of blocks by putting them under the wheels and job done.
BP