50/50. If its bad traffic, no chance. If its not so bad, then you'll make it with time to hit a restaurant at LGA. Cab is the only option if you're short on time, and it should take 30-40 minutes with no traffic. Security can take anywhere from 3 to 20 minutes from my experience. I think traffic is going to not be great, but you could luck out. I've made upper east side to a flight in 40 minutes, but that was early morning.