All restaurants and supermarkets in France are open (subject to restrictions) as are most airports. Le Touquet appears to be open but this restriction mentioned above is a bit strange. The message they display says Air to Air in French only from 11:30 UTC to 13:00 UTC but goes on to state arrive/takeoff before 11:30 after
15:00 if you need English. Of course you can land or take off any time in operating hours by banging out your
verticale or
décollage if you know it. However, amongst all your other paperwork, you'll need to fill in an
Attestation de Déplacement International which you can find here:
Attestation
You probably have to do something similar to get back into the UK?
Might be a bit of fun but don't forget your masks either.