Driving to France for holiday - where to go?

[bassackwards]

Where in France can we drive to relatively easily from London for a week-long holiday around Easter time?? Looking for somewhere chilled where we can rent a house/cottage rather than a city. Will have an 18 mo in the back so want to keep the travel time to a minimum

Ferry to St Malo, then drive to South Brittany. Very child friendly, and lots of places to go.
Or if you want a shorter ferry trip, Dover to Calais or Newhaven to Dieppe then down into Normandy, somewhere near Bayeux.

For minimum journey time, I wouldn't do the ferry - takes 6.5 hours and it will take you longer to get to Portsmouth than it will to Folkestone. I'd take Eurotunnel because you only need to get there half an hour before your booked train and the train only takes 35 minutes to Calais. From Calais you can get to the Loire Valley in 4 and a half hours. We were really impressed with Centre Parcs Le Bois aux Daims.

I love France and find it perfect for those first few family holidays. Perfect change of scenery and pace of life, mild weather, delicious food and wine, spot of art, shopping etc. Southern Brittany coast around Vannes is lovely, also just into the Loire valley/Mayenne not too long a drive.
Sorry to be such a pessimist but I'd be a little worried about the potential post-Brexit travel disaster around Eurotunnel or Folkestone ferries next Easter. Whether we should believe the scaremongering or not they're forecasting enormous queues at ferry ports and not sure of impact on Eurotunnel. If it does all go pear-shaped I wouldn't want to be doing that journey with a toddler.
I think the Portsmouth-St Malo or Caen ferry journey or flights to Nante or similar could be easier. Yes the ferry journey is ~6 hours but you're able to walk around the boat in that time, not stuck in a car.
Hope you have a lovely time.

I live near Vannes in South Brittany and am happy to help with this area if you need any advice.

if you want something really easy just try pas de Calais.
We stayed at a campsite in Guines (about 5 miles out of Calais) for a week en route to EuroDisney. So much to see in this area. Highly recommended.

If not, as others have suggested - South Britanny - Benodet/Pont Aven etc, or North Britanny.

if you enjoy those, you'll enjoy other parts of France.

By the way, if you fancy Britanny, the best way is an overnight ferry to any of the ports. Roscoff saves a lot of driving. I wouldn't try to drive to Britanny from Dover.

We’ve been to the same Center Paris mentioned above, twice. Once was when DS was 18 months and he was fine with the travel. We broke it up with an overnight stay but wouldn’t need to now he’s older. It’s lovely.

Normandy is lovely, & quite underrated (people seem to just fly through on their way further south ) - ferries run from Portsmouth to Caen or le Havre for the main part, or Cherbourg for the Cotentin peninsula.

We had several great hols when the kids were small around Houlgate - the whole coast eastwards from Caen to Honfleur has some really nice seaside towns, & inland are places like Bayeux. Westwards is more beachy (the WWII Normandy landing sites).

I don't know Cotentin but I have friends who love it.