We went from Calais to the Alps in Spring.
We found the Ionity and Fastned motorway network to be very reliable (but expensive). You can download apps for both and input payment details in advance.
We used Chargemap to find chargers. I found the app to b frustrating to use (no easy way I could find to link the Chargemap charger location to Google Maps for navigation, so we went the wrong way a couple of times). However, their payment card was invaluable a couple of times because no other (contactless) payment card was accepted at these two chargers (unknown brand ones, located in a small town and a village). Also, Chargemap have an annoying habit of showing charge locations that are still being built! We thought we'd stop earlier than scheduled for a loo break, and do a top up at the same time but the one we went to (after a quick glace at Chargemap) had chargers installed but wasn't in service yet. Thankfully we were no desperate for a charge. Delving deeper into the charge location details did say it wasn't operational yet.
A friend is using ABRP for their trip and is finding it useful. I've not used it myself yet so can't comment further.
I strongly recommend going to charge locations that have more than one charger, even if they cost a little more. We went to two single chargepoint locations only to find they were out of service.
Many places also just accepted regular contactless payments.
The motorway signs show if there is EV charging at the service stations, but they use a generic sign for all chargers. We stopped after seeing a sign (before schedule again for a loo break (we had two small children in the car too!)) and found they were Tesla only machines. Again, thankfully we were not in dire need of a charge.
Remember that once you're on the motorway network your range is suddenly limited to just 60/70% charge (80->20/10%, and back up again).
I've no experience of using hook up cables at camp sites to charge, hope it goes smoothly for you.
Edit: Oops, just realised this is the hybrid forum! Didn't pay attention to where I was posting. I'm guessing the above info isn't of use for hybrid charging so apologies...