SZ - Lucky [censored]**r. I'd love to have the time to to the whole GR10, you'll love it. I've done bits but current family committments won't allow it now.
A couple of points of possible interest - you could still have snow if you go in June (I did) and late summer there's plenty of thunderstorms (I did), real serious ones not just a few lightning flashes, so make sure your gear is up to that.
Cheers, S.