We have towed extensively with a T/A van on the continent. France/Switzerland/Italy, most recently last September. Never had any problems, other than some site pitches are a little on the small side so you need to be adept at manouvering skills! I do check the Caravan Club entries for all sites in advance though to make sure there isn't a 'no twin axle' rule, as there are some sites that do have this. We never book ahead, as we tour out of season, and like I say, have never encountered any problems. As long as you are a genuine leisure/touring caravanner (and look like it!), a reasonable outfit should be no trouble to you (don't tow with a commercial vehicle). It is unfortunately the 'travelling community' that are causing these problems (in all parts of Europe - inc the UK). Good luck.
Richard.