Plus a restored Montreal train to be useful would most likely need to run overnight like the old Montrealer which would mean stopping in VT in the middle of the night, not something VT is likely to subsidize. In a country that actually cared about rail service the Montreal train would be a new overnight train in addition to the Vermonter but then Amtrak would have to pay for it itself which isn't going to happen under our present dysfunctional arrangement.
As always, it depends...
Looking at the best timetable I can find, SAB-NYP is about a 10-hour run (I found one with a 9:55 run SB [1]). It might or might not be accurate, but since Amtrak won't give out a timecard anymore it's what I'm going to work with.
Let's presume that the "no go" hours for a given stop are 0000-0559. I'd note that a straight 12-hour "flip" SB would have every stop in Vermont covered prior to midnight save for Brattleboro, and you'd still get into NYP just after 0600. So this does not seem like an unreasonable schedule. Sliding it around a little bit (and perhaps adding a minimal additional pad at SPG or NHV) would get you into Brattleboro before midnight and hit NYP at just after 0600. NB, it takes a
little bit more fiddling, but I think you can either get every stop or close to it outside of the graveyard shift. By the way, one other viable option here would be to just add a few intermediate stops (e.g. the various Springfield Line stops and NRO) as a method of "padding without padding". Given the operational hours, demand would probably be light (but would not, in aggregate, be
zero, I suspect).
The bottom line is that Vermont might be willing to sponsor a train that provides access to Montreal in the morning/from Montreal in the evening and which provides access to NYC and points south without killing most or all of a day en route.
Edit: I would note that this was the Montrealer's schedule SB. NB, service to Vermont was pretty well buried in the middle of the night (as a consequence of trying to serve WAS-NYP earlier). I suspect that could be worked around. I'd also note that in an ideal world, VA and VT would be able to talk out a cost-sharing deal on a train since VA has a bit of a problem with "too many routes and too few trains" in the afternoon/evening. Honestly, arranging for a big pad for both of them and running one train Hampton Roads-Washington and another Roanoke/New River-Washington and then sending one off to Montreal while the other goes to Boston isn't actually
that unreasonable, and the "new" evening train out of Newport News is timed almost
perfectly for the above.
[1]
Amtrak - Vermonter Timetable