Paul
1. take your son with you, you can fit the car seat he uses to mots (if not all) 4 seat types that I'm aware of
2. flying in France (and other places too) isn't about how far you can go but the places you can land (mostly free) and what you can do/see/eat when you get there
3. Don't give up unless you really have to. I did, through financial reasons, and now regret it so I'm looking at starting again
all that said, when you get round to making the decision, don't look back.