I was thinking we could our Carnac B&B as early as possible (figure 9am?) and drive about 1-1/2 hours to the Forest of Broceliande(aka Paimpont).
Find one of the tourist offices with maps (Tréhorenteuc) and spend some time looking for at least some of the "Arthurian" sites (val sans retour, some dolmens ("merlin's tomb"), lake, some interesting trees, church w/ Grail theme stained glass)
Then drive the other hour in to Rennes. Turn in the rental car (which I will have rented in Bordeaux almost 2 weeks before).
Take the next possible train to Paris (about 2 1/2 hrs).
* Has anyone been to Paimpont Forest? I find no mention of it in the forums here. If so how long is reasonable to spend trekking around it? I'm unclear as to distances and times between stops, driving or walking?
* The hotel in Paris on it's info page says to let them know when you make a reservation about "late arrivals" which they define as after 6pm! I'm thinking between about 7-9pm is likely, but it could be earlier or later. wondering what I should tell them?
* Would the train from Rennes to Paris have food available so we could eat a light dinner in transit?
* If I say I'm returning the car in Rennes, will they be disturbed if I return it closer to Carnac instead? (probably renting through europecar or similar - would be small manual transmission car picked up in Bordeaux)