As long as I get the annual leave approved we’ll be heading to France via Eurotunnel. We usually get the ferry, but Eurotunnel seems safer as we won’t need to get out our motorhome.
All I’ll do is ensure I have a travel/ health insurance policy in place first (before booking Eurotunnel) that covers us if we need to cancel related to Covid (or any other issue). I know our Ehic cards are in date so that’s fine. I always ensure the policy covers us for road cycling and mountain biking (not all do).
We don’t need to do anything special regarding vehicle insurance/ rescue/ relay service as ours covers European travel. We have all the gubbins in the van already for travel in France (eg breathalyser).
We camp wild or use aires so nothing will be different there. For you I guess it depends where you stay and what you are happy with - eg shared facilities of a campsite, or booking a gîte and if you feel the need to clean it first.
Our van will be stocked up with food, but we’ll still need to food shop for fresh bits as we go which doesn’t concern me.
We don’t tend to visit attractions. You’d need to consider that and check out what’s open and what measures are in place then decide if you’re happy with it.
Normally wherever you go it’d make sense to be mindful of where the nearest A&E is anyway, just in case.
Other than going via the tunnel I don’t really see our holiday as being any different to normal.