I have done this now a few times. Wife doesn't ride, doesn't care about it at all. We both work from home, no kids either.

We just came back from a 2 week trip to France. I rode the Etape, did Alpe D'Huez, rode Ventoux, and did two other rides around the Luberon. She drove to many of the places I rode (Modane, Ventoux, hilltop villages in Luberon) - but stopped along the way at markets and shops and other places I didn't care about. Riding around the hilltop villages of the Luberon, we met at a couple of them for coffee, lunch, a drink. Riding up Ventoux, she came later and met me at the top, and we went off together to visit lavender farms and such. It worked really well.

My advice - at least what works for us:

- If you can find a like-minded couple to go with, that is awesome - you both have someone to be with (I rode with my brother, my wife hung out with his wife). Not always possible though.
- Don't ride every day, and like eippo1 said, have a plan so you both know when you will be together and do 'together' stuff.
- Don't ride all day either, so you spend some time together every day.
- Make sure she plans some stuff to do together that she loves, even if you don't. Encourage her to do some stuff alone that she really loves too. You should both be doing some stuff you love.
- Make it special when you are together - a nice dinner, a spa (we did these several times - great for aching legs!).
- As mentioned, shopping is always a good thing for the womenfolk, as I understand it.

Hope this helps. My wife and I did it this way - not entirely premeditated - and it worked really well. We had a ball.