Have you guys been following the ‘attestation d’accueil’ discussions by the way?
https://france-visas.gouv.fr/en_US/web/France-visas/your-arrival-in-france
It seems visitors from the UK might be asked at the border to show proof of health insurance, sufficient resources, and accommodation booked - or if they are staying with family or friends an attestation d’accueil (30€ from the Mairie).
Don’t you just love brexit?