triple5soul
I can't recall what last year's deadline was, but some R2 applicants began receiving invites a few days later.
For R1 the D-Day was Oct 26th and the deadline was the 14th, so give or take it's two weeks after the deadline.
My only advice on this is to relax and focus on other apps if you have more to go...if not, just go out and party until you are up for receiving invites.
One thing I have to say is that in my experience, the admissions process at Booth is very professional and as transparent as an admissions process can be...