So I worked out a few scenarios for possible Vermont trips.
For all the schedules are basically the same whether a weekday or weekend. I'll use New York City (NYP) as an example, but start/end points for the Vermonter could be anywhere on the Northeast Corridor. Start/end point for the Ethan Allen Express has to be New York City. Times for Burlington (and startup date) not yet known, but figure about 10 PM arrival, and about 10 AM departure.
A Vermonter-only round trip to St. Albans would be 2 days:
Day 1: Leave NYP 11:33 AM, Arrive SAB 8:50 PM on Train 54 or 56. Stay in SAB.
Day 2: Leave SAB 9:15 AM, Arrive NYP 6:25 PM on Train 55 or 57.
An Ethan Allen Express-only round trip to Burlington would be 2 days:
Day 1: Leave NYP 2:20 PM, Arrive Burlington approx 10 PM on Train 291. Stay in Burlington.
Day 2: Leave Burlington approx 10 AM, Arrive NYP 5:45 PM on Train 290.
Now to combine the two would involve a stay somewhere in the New York City area, or south of there along the Northeast Corridor (with a Regional connection with the Ethan Allen):
Day 1: Leave NYP 11:33 AM, Arrive SAB 8:50 PM on Train 54 or 56. Stay in SAB.
Day 2: Leave SAB 9:15 AM, Arrive NYP 6:25 PM on Train 55 or 57. Stay in New York City or elsewhere.
Day 3: Leave NYP 2:20 PM, Arrive Burlington approx 10 PM on Train 291. Stay in Burlington.
Day 4: Leave Burlington approx 10 AM, Arrive NYP 5:45 PM on Train 290.
The opposite would work too, doing the Ethan Allen the first 2 days and the Vermonter the second 2 days.
I looked at the possibility of doing the whole thing in as little as two days, by taking the Vermonter one way and the Ethan Allen Express the other way. Either we take 54 or 56 to Essex Junction, Uber/Lyft to Burlington and stay there, and then return next day on 290, or we take 54 or 56 to St. Albans and stay there, and then we would need to Uber/Lyft from St. Albans to Burlington. The schedule of the Vermonter would have us depart on 55 or 57 at 9:15 AM, arriving Essex Junction 9:44 AM. This would not give enough time to get to Burlington for an approximately 10 AM departure of 290.
The converse of the above would be to do 291 to Burlington on Day 1, Uber/Lyft to St. Albans, stay there, and then on Day 2 take 55 or 57 back to New York City. Or... Stay in Burlington and then on Day 2 Uber/Lyft to Essex Junction to catch 55 or 57 there.
And finally, I also looked at connecting between the two routes by using the Lake Shore Limited. It would not save us any time as it would still take 4 days... plus the connection at Springfield, MA between 55 or 57 and 449 is too tight (arrive 2:35 PM, depart 3:26 PM) and the connection in Albany, where we would have to stay, would be 23 hours (arrive 6:10 PM and depart next day 5:05 PM on 291). A connection involving 448 eastbound does not work at all in either Albany or Springfield.
No matter what we do or where we go, we're going to take a financial hit on hotels. Costs aren't what they used to be, but then inflation has hit everything. Burlington, VT always was highly priced, unless one travels a mile or two east from downtown where a cluster of many hotels sits near I-89 and US 2. St. Albans just has the Hampton Inn near the station, and it's been high but we might catch it during the week cheaper than it would be on the weekend. New York City.....well that goes without saying that it may prove prohibitive any day of the week, and most NYC hotels are simply boutique cubbyholes not much bigger than the bed itself. The high hotel rates may be a signal to limit this to just a 2-day round trip.
I had planned a trip (yet untaken) for myself to St. Albans via the Vermonter, but to minimize the time on one train, I would take 4 days (rather than 2) to do it, making overnight stops on the way in Connecticut. That personal itinerary is here , but again if we adapted that for a Fest, it still does involve 3 hotel nights. The thought behind this option is that the Vermonter uses the half BC/half café car, so there are only 18 BC seats available which often sell out along the Northeast Corridor. Using the Vermonter only between Connecticut points and Vermont increases the chance of getting decent seats on that train.
All stuff to keep in mind, but the intention here for July is to stay in the north to avoid summer heat.