In response to several replies about having pickups/setouts at other than endpoints I have several thoughts:
1. To stop the train, make a cut (behind the locomotives?), proceed forward to a point beyond the switch, backup to make the hitch, test the connection, proceed forward far enough the last car clears the switch, back down to the disconnected passenger train (yep, the passengers are without HEP the entire time!...no A/C, no heat, no functioning toilets!), make and test (a slight yank) the hitch, make air and electric connections (would that require a craft position other than onboard conductors?...or a local yard switch crew 'on standby' waiting for the train to arrive?), perform a brake test, then wait for a clear signal to highball. That's 45-60 minutes on a GOOD day! Meanwhile, passengers whose cars were just added to the train, where were they the whole time? Presumably the train originally stopped with the sleepers in front of the station. But then you get into safety concerns with disconnecting or connecting to the train and the attendant jolts and boarding in the dark at night without HEP. Recalling the fun and games of simply adding or subtracting M&E cars and sometimes Roadrailers to the Amtrak trains I was on, 30-60 minutes was the 'normal' time. And that was usually at the rear of the train, not somewhere up front. I was angered every time at the those delays. 15 minutes would be OK, but 30 or more, no way!
2. Added costs likely exceed the revenue generated. I'm thinking that like the intermodal business where short-hauls don't make business sense, I suspect there's some not-yet-determined 'magic number' of miles and revenue that makes business sense for an Auto Train operation. Would a 500 mile Auto Train make money? I don't think so, especially since it can be comfortably driven in 8-9 hours including a couple of rest stops.
3. Chicago-Denver was suggested and makes sense as it is quite close in mileage with the existing Auto Train. But is there sufficient demand? Perhaps a check of pre-Covid airline schedules WAS to Florida compared to Chicago to Denver might be a gauge. Note that I said Florida rather than Sanford as there's countless destinations within Florida easily accessed from Sanford, especially Disneyworld, and major cities such as Orlando, Jacksonville and Tampa within a 2 hour drive. Arriving in the morning in Florida makes south Florida accessible in the day as well. The snow-bunny business is big business to/from Florida, both for vacations as well as all winter. How many travelers would spend the summer or winter in a cabin in the mountains? How many major destinations are within a 2-3 hour drive from Denver? How many attractions comparable to Disneyworld are near Denver? Maybe skiers could be enticed in the wintertime, and hikers/campers in the summer, although I suspect there aren't enough of them to make that a 'demand' level.
4. I think that a separate Auto Train location would be necessary for all points, including pickup & setout points. For example, how many passengers would be happy to leave their car in the covered 'drop off' area at Chicago Union Station to a stranger that promises to get it loaded on the trilevel autorack 5 or 6 blocks away? What about arrivals? Where would arriving cars be parked so passengers can pick them up. Clearly, locating out town such as Dyer IN or Galesburg IL would work best, especially with low-cost land available. Locating on the best rail line from Chicago to Florida or Denver is also crucial. Knowing firsthand how CSX gives the Cardinal the shaft on the ex-Monon line, I'd definitely consider another railroad out of Chicago for ramp placement decision making. By the way, the location should be an easy off/easy on in both directions to a freeway. Wandering down country lanes for 10 minutes could certainly lose some drivers.
5. And, of course, would the railroads involved be willing to host an extra Amtrak train each way without paying them an arm and a leg for such things as extra sidings, new signaling, and anything else they can dream up. When Covid is over and done with, and Amtrak returns the LD trains to daily operation, anyone want to bet the railroads WON'T charge Amtrak extra to 'add' 4 extra trains per week to the route? Lookup the ridiculous numbers UP and CSX have come up with through the years to make the Sunset Ltd and Cardinal a daily operation for the answer.
While pie in the sky thinking is what motivates business expansion as well as new business creation, one must always consider what is the 'market' for the product and both the startup and ongoing costs of running the business. "Build it and they will come' doesn't automatically spell S-U-C-C-E-S-S. Investors want to be very sure they'll get a good return on investment before they'll put down millions of their money. Or, if pure speculators, they want a big portion of the business ala 'The Shark Tank'.