I'm going to go over on the Euro Tunnel, do an over night stop on route to Geneva and the same on the way back so again, if anyone know's of a good Morgan friendly hotel on route it would be appreciated.
Depending on which way you're going, we've stayed when driving from Paris to the mountains in Chablis at
http://www.hostellerie-des-clos.fr/ which is not too far off the A6 autoroute after Auxerre. This is about 2.5 hours from Geneva. The hotel was cheap (the room was about €80) clean and reasonably comfortable, but we found the restaurant really top notch; we spent considerably more in there than we did on our room. As I recall 'er indoors had oeufs en meurette (eggs poached in wine - a burgundy speciality) & I had a fricassé of snails to start, than we both had lobster cooked 3 ways as a main course, all washed down with lashings of excellent Chablis. The patronne arranged for the Morgan to sleep indoors with the tractors in a wine chai round the corner. All in all an excellent stay.
As to the breathalyser - you need to have two (in case they ask you to use one, so you still have one when you've done so) and they need to be NF (normes francaises). You can pick them up at a petrol station, or the eurotunnel terminal.
If you are going to drive on swiss motorways you'll need to buy a vignette when you pass through the frontier (about €40 as I recall, but valid for the whole of 2013) Watch out for the speed camera as you approach the frontier post as the speed limit gets brought down in increments - it's just after the final speed reduction & it's easy to get flashed as you're concentrating on trying to work out which lane you should be in (you can probably guess how I know about that one....)