I am in same boat as you are, I got request on 27th march. I send all documents via email on 31st march around 10 attachments - 18.5MB. In letter says for fast process send via email.
I haven't heard any thing from them yet or change in status online. Via web form and online document upload have limit of 3.5MB. even I compress all the file to 3.4mb. still not able to send it via webform.
So I am hoping the email I sent is good and in couple of days status might change to document revirew.
IS you file in Mississauga? and do you know the address for sending documents?
Thanks for the question