I'm also in a situation where I'd like to know if this is possible.
I'm still using Contact Form 7 version 3.3.1 because it's the latest compatible version with Contact Form 7 Textarea Wordcount, which is no longer in development.
has this feature been added to the newer versions of Contact Form 7?
IIRC, 3.3.1 CF7 only supported text box character limits, but nothing for text areas.
Thanks!!