That would require a massive premium, Tony!
A serious point about insurance for Caran:
Remember that your EHICs get you the same free, or discounted, health provision in France that French nationals get. Click 'Health Services and Costs' here:
http://www.nhs.uk/NHSEngland/Healthcareabroad/countryguide/Pages/healthcareinFrance.aspx
The 'health' element of travel insurance is only needed for
(a) any costs that aren't covered by your EHICs ;
(b) repatriation costs if, say, an air ambulance is required to get one of you back to the UK ; and
(c) the costs of cancelling your holiday if one of you is too ill to travel.
So travelling abroad without insurance might not be particularly risky. (I don't usually bother).