Don't know if this has changed, but the last time I did this (NYC sleeper from Chicago, coach to Boston due to a bad ordered BOS sleeper) you may not be able to switch between cars at Albany. The train was split and the BOS section went through the station first, then the NYC section.
Our sleeper attendant had us switch at Schenectady. The other sleeper did not, and almost got left behind at Albany. We had to back up to get them.
That sounds weird. Every time I've taken the LSL east-bound, the train pulled into Albany, everyone destined for Albany or elsewhere who wanted to get off did so, then they closed the doors and split the train. The Boston section pulled forward, then backed into a different track (on the other side of the platform), the New York engine backed in and coupled to the NY section (the back end of the train) and the attendants re-opened all the doors. The people who had gotten off got back on, as did all of the passengers waiting in Albany for either Boston or NY, and then the trains left. The split took about 15-20 minutes.
Last time I did this was just about a year ago. There were no through roomettes from CHI to BOS, so I was in an NYP sleeper to ALB and had to switch cars. They told me when I arrived I had about 5 minutes to walk ahead to the BOS sleeper, or I could wait until after the split was complete. Since ALB has high-level platforms, the weather was beautiful and it was easier to switch cars on the platform (more room to maneuver) there than to walk through the train, I had no problem dragging my big wheelie duffel bag about 6 car lengths in the time allowed. I put my bag in my new roomette and then went outside to watch the split. I could have stayed in my new room or gone upstairs at the station for a snack or something but I wasn't hungry. We had over an hour in ALB before the train left, so there was no rush.
I didn't even consider switching at SYR or after, and didn't ask if it was possible. Syracuse is only a quick stop.
The do feed you "dinner" after the train leaves Albany, but it isn't anything to look forward to, usually. One time, when there was no Boston sleeper for some reason, they put me in a NYP sleeper CHI<->ALB (both ways) and in Business Class on the ALB<->BOS section. Westbound, the lunch was a fairly decent sandwich, but eastbound, the "dinner" was a salad fresh from the freezer, mostly iceberg lettuce with quite a bit of iceberg still in it. Fortunately, my plan was to take the Red Line from South Station to Alewife where I would meet some friends for dinner at Jasper White's Summer Shack across the street. After watching the Red Tail hawks in the parking lot for a while and having a fantastic sea food dinner, they gave me a ride home. So I didn't care about the frozen lettuce!
