We had friends that came in last Saturday around 3:00, which is the busy time, and they were through the arrival process, went to get their car and were at Oyster Bay, an hour away at that time of day, by just after 5:00.
So I would say things have been better than when the temporary facility was first opened. There are fewer planes around 4:30 so you should not have a problem but just to be sure could go ahead with wheelchair service.