I did almost exactly this on May 31. There were no roomettes available from CHI to BOS, so I had a 48 (NYP) sleeper to Albany where I moved to the 448 sleeper. I got off the 48 sleeper and walked all the way forward (with my luggage) to the 448 sleeper. The attendant told me they weren't boarding yet, but I explained I was moving from the the 48 and he said fine and let me board. I think if the 448 roomette had just been vacated, he would have wanted time to clean it and make it up, but apparently that had already been done. (Perhaps the passenger had gotten off at an earlier stop.) After putting my luggage in my roomette, I got off the train again and watched all the proceedings from the platform.
They did close the doors during most of the interval, but I don't remember the Boston section moving to a different platform. That was over a month ago and sometimes I wonder if I can remember anything any more, and it seems logical to me that they would have pulled the Boston section forward past the end of the platform and then backed in on another track to allow the NYP engine to back in and couple to the New York section on the original track, but I don't remember that happening. Possibly, they did that while I was still in my new 448 roomette.
In any case, it is almost impossible to miss the connection. I think you would have to go upstairs to the station, put in earplugs so you couldn't hear the announcements and then go to sleep in the waiting room. Or exit the station and go for a long walk. When you arrive in Albany, just gather up your belongings and ask a conductor or your sleeping car attendant what to do. They will point you at the NY coaches.
BTW, you could haul your luggage back about 3-4 cars to the first NY coach, but it is much easier to do that on the platform. You will have plenty of time. If you get stuck on the platform while they re-arrange the train, I think there are benches if you want to sit.
Oh, and the Sleeping car attendants will bring your meals to your roomette. Sometimes they volunteer and some times you have to ask, and one time (Coast-to-coast round trip on 6 trains, mostly in roomettes, so lots of meals), they took my order and then forgot to deliver it, but the attendant was extremely apologetic and rushed off to get it as soon as I reminded him.
I always do something similar as the OP, but take a New York section sleeper CHI-ALB to be away from the train horns and to be close to the diner...er...sleeper only food car. At ALB, I switch to the Boston section coach to Springfield.
My method is to leave the sleeper as soon as the SCA opens the door and walk down the platform to the BOS section and immediately board. Passengers will still be deboarding the train, so all doors are open. Doing that avoids the Albany-boarding crowd and provides a much larger choice of seats. I've done this at least 25 times or more through the years and never been challenged on the platform or in the coach or business class section of the cafe/BC car (now replaced by full cafe). For what it's worth, I'll be riding the Lakeshore from CHI to SPG on Thursday!
Of note is that the Boston section sleeper is the first car of the train. That means that at Chicago, it will be the furthest away from the doors to the platform. Once aboard, to get to the diner, you'll have to walk through the cafe car, then 4-6 coaches. Alternatively, the sleeping car attendant may be willing to get your meals (breakfast & lunch) for you.
At ALB, all coaches past the 2 immediately behind cafe car (and your sleeper) are New York coaches as those first 2 go to Boston. Once aboard a coach, look at the seat checks for passengers still on board to make sure there is a preponderance of 'NYP' (New York Penn) written on them. Then you'll know you're in the NY part of the train.