Allow extra time to charge fully (free!) at Eurotunnel Folkestone. Get a KiWhi card, and use free Auchan chargers but have a plan B as they can be occupied for long periods. Use Chargemap for planning. Have Plugsurfing tag or NewMotion card for Corri-door and others.

It'll be straightforward and you'll have no problems. I haven't charged in Paris, but I'm sure others here will be able to help on that.

 

I've done this journey twice in my Env200 and got away without having any RFID cards at all! Auchan supermarkets usually have chargers and those that do need an RFID card, you need to go to the Auchan Customer Service desk and they will lend you a KiWhi card in exchange for your ID card or similar. Keep hold of the card until you stop the charge since the machine won't disconnect you without it (as I discovered almost to my peril - I returned the card before finishing the charge and then they closed the store early [it was Easter Sunday!] and I then couldn't disconnect! I had to bang on doors and beg a security guard to let me in again to retrieve the KiWhi card!)
Other Auchans don't require the card and are even open 24/7 (if they don't have barriers at the car park entrance). It seems Nissan have their own RFID card but this is for French residents only I think. We also recharged at Nissans - all free and without the need for the RFID card.
Now planning a longer trip but am definitely getting myself more RFIDs...