Polarbear2,
I've done a few driving holidays to the south of France myself in my later 60s, and while it's not without its challenges, it can be a rewarding way to see the country at your own pace especially with a nice car to enjoy. You're right to think about the long hours; the drive from the UK can feel endless if you push it all in one go, but breaking it up with overnight stops turns it into an adventure rather than a slog. We always aimed for no more than 4-5 hours driving per day, stopping in charming spots like Reims or Dijon on the way down, which gave us time to stretch our legs, wander markets, and actually relax without feeling rushed.
To keep boredom at bay, audiobooks and podcasts were lifesavers for me nothing beats a good story to make the miles fly by. And yes, sharing the driving if you're both comfortable with it makes a huge difference; my husband and I swapped every couple of hours, which kept us both fresh. France's roads are generally a pleasure quieter than the UK motorways outside peak times, with stunning scenery once you veer off the autoroutes. Just plan for tolls (they add up, around €50-70 one way) and book hotels in advance for peace of mind, mixing in a boutique stay or two to match that fantasy without breaking the bank.
For the crossing, we found the Eurotunnel a straightforward option from Folkestone 35 minutes and you're in Calais, no seasickness worries, and you stay with your car. If you're plotting the route, this chunnel guide has some practical tips on timings and prep: chunnel.co.uk/. Give it a try; you might surprise yourself and end up loving the freedom. Safe travels!