I think skipping the Loire is a good idea this time since you are going to have so much to see with the other places you are going. Do you happen to know the name of the church or other details of the Vaux visit? I ask since we have lots of history there as well. A childhood friend has spent hours collecting old photos of all the little beach towns there and so we have amazing digital scans of the Vaux Saint Palais, etc. back in the late 1800's. Very cool to look at the history. What a fun and personal event, and opposed to years ago, the beach is hopping in June, which didn't used to be the case. BTW, here a couple of good restaurants in the area if you have time while you are there:

In Vaux, the one I would AVOID is the Maison Blanche-we are disappointed every time.

We have heard Le Bel'M is good but haven't tried it http://www.le-belm.com/

In Royan, l"aquarelle is the "big deal" place Michelin 1 star: http://laquarelle.net/

I don't know great place there, but in Saint Palais which is 5 minutes away, these are the ones we like

In Saint Palais, Les Agapes is the most gourmet choice, good but more formal than we usually go for at the beach-but nice people:

http://www.les-agapes.fr/

This is our favorite dinner place because it is right on the beach between Vaux and St. Palais:

http://www.restaurant-l-arrosoir.fr/

This is our favorite casual place for crepes-the owner is Breton so everything is really authentic:

http://www.les-quimperoises.com/

And this is the new cookie/gourmet food gift place that opened last summer. Super nice people-many of the cookies are actually more from Brittany, but delicious and a great place to find gifts to bring back:

http://www.biscuiteriedesaintpalais.com/

Have a great trip! we probably won't get there til end of summer this year because we are getting settled in our new part time place in Seattle after Peace Corps service in Mexico, so lots of changes for us this year.

Agree, I have never had a problem renting a car on the outskirts of Paris and driving away from it . . . in your case, you'd get on the A13, heading northwest.

Easy!