I guess I'll just have to slum it in coach from Philly to Orlando
A lot of us ride Amtrak in coach and/or a sleeper compartment, and don't think of coach as 'slumming'.
Depends on what you mean by "sleeper". I've had some crazy arrangements, including "2nd class" on a river cruise in China in the 80s. There were actually two 2nd class types on the boat, and they were all shared two beds for two passengers. They also had a lower 2nd-class that we initially got even though we paid for upper 2nd class. And no there wasn't a 1st class.
I remember passing by the 3rd and 4th class accommodations, which were communal bunks like enlisted quarters on a navy ship. I think 3rd had 8 to a room and 4th 12. My understanding is that some train systems around the world have similar arrangements.