Not dissimilar to my thinking when we did our trip a few weeks ago.
My stop on the way down was Thurrock, where we charged to 85% because I had to bump it to have time to eat.
I knew that would then allow me to either charge at Folkstone or if busy and unable, to then continue regardless.
Similarly, I didn't want to discover on my first trip with the Tesla, that "world plus dog and the mongrels" all piled on at Coquelles and as such we could get further into France where people would have spread out by then.
Next time I may do it differently though but I try to plan my stops where I think most people aren't doing it by force of choice.