The 1st level Druid spell Shillelagh allows you to deal damages two sizes higher. Does this spell actually increase the size of the weapon? Would this give the weapon reach? Looking for both a RAW interpretation and possible DM rulings that might make more sense than RAW.
Shillelagh (Druid 1)
Your own nonmagical club or quarterstaff becomes a weapon with a +1 enhancement bonus on attack and damage rolls. (A quarterstaff gains this enhancement for both ends of the weapon.) It deals damage as if it were two size categories larger. These effects only occur when the weapon is wielded by you. If you do not wield it, the weapon behaves as if unaffected by this spell.