Going to go with option #1.Transferring between two different airports (involving one which is a train wreck in terms of passenger access right now) mean doing as much as possible on grounds would be my option.
One recent article on LGA... ".
More people are biking to LaGuardia, particularly since airport construction expanded about a year ago.
At certain times of the day, automobile traffic is so bad that biking is the only way for airport employees to get to work on time. In addition, delivery workers and neighborhood residents picking up or dropping off rental cars bike at the airport."