Should i upload extenuating circumstances or wait?

I am an international undergraduate applicant applying to mcgill. I have yet to receive a response from them. My application status is “Reviewed decision pending”. My checklist is complete. I recently received my term 2 grades and they are lower than the grades i submitted already due to some extenuating circumstances. Should I
1: Do not upload the updated and weaker transcript and wait for a response or should I
2: Upload the weaker transcript and write a letter of extenuating circumstances