I don’t typically expect saves to require an action; they’re more an instinctive reaction to whatever else is happening. I’d run it like, if you save successfully and then attack, then cool, you get to make a normal attack, but if you fail to escape and try to attack anyway, it’s probably impaired (d4).
This is all kind of relative based on context, though, which is why there’s a general “treat combat maneuvers as saves” rule but no specific grappling rules. If you’re grappling a giant porcupine, the spines are attacking you without being impaired! It’s kind of a “use your best judgment and change the approach later if you need to” philosophy.