I've received a 2 hour appointment request for Super Bowl Sunday at kick-off time. I don't mind missing the game, but what is the traffic/parking going to be like? How crazy will it be to navigate through a Vegas casino to get to my client's room? Will security be extra tight?

And depending on what hotel you are going to parking could be an issue if you valet.If you self-park it should not be a problem but I would advise to give yourself more travel time.
I recall last year I went to a hotel (no fees charged at the time) but at valet the guy had the check-in list and was confirming first and last name of the guest to valet.
If the hotel has security just have him meet you somewhere in the hotel and go up together.

You're very nice, jaydalee! Thank you for the helpful information.