"long train ride"

[gemt]

For this you need a bank card that you can use online but does not have a PIN (that you know)
This will work in the UK, you need to check details in other countries:
1) Online train tickes
2) Issued from on-platform machines
3) Requiring the bank card as identity
4) Not requiring a PIN number
5) You would need a pin number to use the card for, say, a taxi ride home.
6) Or use a prepay card with no credit left

You pre-book some 1-way train tickets to be issued by machines at a series of stations using this card.
You need to carry the card but don't need a pin to collect [please test this out], so now you can plan on a whole chain of train journeys, with no way to back out.

You could get someone else to do the booking, so you have no idea where you are going! They just have to give you the list of reference numbers in the correct order. I'm not sure what lockdown policies might apply if you had to try all the numbers at each station.

In the UK there are also a few towns with two stations, so you would have to walk from one to the other, or you could get "plus bus" on your ticket.

If you are going to do this, get open singles, as you don't want to risk messing up on an "advance" connection.

Add in to this whatever the appropriate fetish, probably involving clothing. Once you are on the first train you are stuck with it until you get home!