Frankly I can see two trains to Montgreal, one funded by NY and one by Vermont. I have difficulty seeing a third train being funded by anyone. Also, ubless someone other than Vermont ponies up for an overnight train I think it is unlikely.
Depending on crewing situations, timetables, and the like? I could see a situation where Vermont pays for "both Vermonters" to go to Montreal because of crewing efficiencies and the like (i.e. ensuring proper rest periods for the crews running north of...wherever they split the crews) or if the extension was "revenue incremental" (i.e. the added ticket revenue from the extension is more than the added cost of extending). But I suspect they would both be daytime trains.
For what I'm thinking, let's assume the following:
-SAB-MTR: 90 minutes (this was about two hours on the 1994 timetable, but as I understand it some improvements are programmed) less any customs stops
-30 minutes can be reduced between NHV and SAB and the NHV stop can be cut to about 10 minutes with dual-modes.
-Times on the current Vermonter will not be altered south of NYP (mainly chosen so I can ignore WAS-NYP for a moment).
On the current (above) Vermonter timetable this would yield:
NYP 1133 | 1825
NHV 1311 | 1639
NHV 1320 | 1625
SAB 2010 | 0955
MTR 2210 | 0755
One thing to note here is that I'm not certain that, report times being what they are, the crew would have a legally sufficient rest period in the event of even a mild delay (since the report time in Montreal would be somewhat before departure). Now, here's a second timetable with two trains per day.
| || |
NYP 1133 | 0805 || 2100 | 1755
NHV 1311 | 0945 || 1920 | 1609
NHV 1320 | 0955 || 1910 | 1555
SAB 2010 | 1645 || 1220 | 0925
MTR 2210 | 1845 || 1020 | 0725
The latter timetable simply extends the first morning Regional from WAS (departure time 0430, arrival time NYP 0746) up to Montreal. I'd note that if connectivity at NYP isn't a major concern, you could slide that another hour (or so) earlier. I've roughly connected the new southbound train to the old schedule for 187 (a NYP-WAS Regional that left at 2110) from 2016. I'd note, again, that if connectivity isn't an issue this train could be pushed later, as below (linking it in with the schedule for 179/479):
| || |
NYP 1133 | 0805 || 2250 | 1825
NHV 1311 | 0945 || 2110 | 1639
NHV 1320 | 0955 || 2100 | 1625
SAB 2010 | 1645 || 1410 | 0955
MTR 2210 | 1845 || 1210 | 0755
Note that on weekends, 179 was 169, and 169 ran through to WAS, so this pairing wouldn't be half-bad. I've reverted the existing train to its (approximate) present timetable. Both trains run through; they can pair with or run through as trains to Washington, DC (I don't think that southbound OTP for a train arriving after midnight is a big deal). Four hours of spacing is pretty decent - I could push them a bit further apart if sacrificing either serving WAS or MTR (I'm not sure which would serve Vermont better, TBH). Of course, I'm not sure that arriving into NYP after 2300 is particularly attractive (and though an earlier morning departure might be more easily sold, I'm not sure I'd want to lose inbound traffic from the New York area to earlier required departures).
Do note that the existing Vermonter crew (arr MTR 2210) would likely turn as the crew for the "new" train (dep MTR 1210, so a 14-hour layover) while the new train's crew (arr MTR 1845) would likely turn as the Vermonter's crew (dep MTR 0755, so about a 13-hour layover), both being rather friendlier to rest requirements.