Even if the POH were to list a maximum range, then this will be the max range under optimal circumstances. High or low as appropriate, power and leaned back for max economy, straight line etc. You'll rarely be able to fly like that in Europe with all the controlled airspace, climb restrictions etc. in the way.
Plus the max range will be assuming nil wind. Hardly likely on a 500+ nm flight.
So better plan your route and altitude and see if the plane can handle this than work the other way around.