There're folks who live in Philly that drive to work when they're based in NYC. The turnpike is normally pretty reliable, it's the river crossings that will get you. Luckily no one likes to fly out of EWR because of the tough mass transit situation to get EWR since few people have cars. There will be times where it'll be faster for you to park your car in Jersey and then take mass transit in because the bridges and tunnels are blocked, but those situations are pretty unpredictable, like a presidential visit. At any rate - my experience was it took about 90 minutes to get from exit 7 off the NJ Turnpike to LGA pretty reliably.