I arrived at the airport at early and would have had plenty of time but my boarding pass wouldn't scan and I had to get into this line to get it worked out:
There had been a shooting at a nearby airport and people were trying to reschedule on to new flights. There were 100 people on the standby list for my flight!
I made it with just in time before the plane started boarding at 5:25.
Miami - LaGuardia
Flight #2.... New York - Montreal
Last Flight Montreal - Home