Definitely go larger. I thing French children must all be stunted or something!
For age 2 it describes as "up to 2yrs" but Imogen was pushing out of it by the end of summer, disappointing as she is only just turned 2 now.
Have you just had that flyer through with the £15 off? I'm tempted by those raincoats but would have to get age 4 if I want it to fit in autumn as well, so it would probs be too big this spring and fit ok next spring when she is 3, but then might not fit the following autumn!
If I didn't love the designs so much I'd say sod it cos they're quite dear for what they are really!