You can always take an earlier train than you're booked on. Unless the train(s) have a "business" car, there are no reserved seats. Seats aren't guaranteed on Amtrak unless you book a seat in a "business" car.

The problem with getting an earlier train is that I "think" that you need to first exchange your ticket at a the Amtrak window in Penn (that's what I've done in the past). That can be a lengthy process as the line can get long. You should call and find out if you can just board the train with a later ticket.

Have you considered taking CT Limo? I think it's only about $40 and it leaves from JFK on a pretty regular basis.

I have two trips coming up in/out of JFK and plan on taking CT Limo (http://www.ctlimo.com/CTLimo/Connect..._-_CTLimo.html). They pick up/drop off in Farmington (just off of 84 by the Finneman Rd exit) and at a hotel near Brainard airport).

bert