Since a Gargantuan Dragon has a 15´ reach and the thrice enlarged AMF covers him very "tightly" is it understood that he can stick his neck out of the AntiMagicField and use his Breath Weapon ?! His claws most certainly will leave the AMF....
Fast arguments against could be that the Breath Weapons comes from further down his body....
Arguments for is that the 40x80 space is the minumum necessary for this big lizard... that when he really stretches out he can have a good amount of body outside the field for that quicky Breath Weapon on those insolent humans.
