Illumination is able to cut costs by limiting story and animation budgets. Usually the films cost around $70, I assume the extra $5 mil was due to the rewrite, which is rare but hilariously it was of course done to make the main character more likable. Because THE GRINCH needs to be likable yknow.
Anyways, it's not a shock that it's profitable as hell. Wake me up when one of these films finally bombs.