Not sure the pile of CDs theory is as unlikely as it sounds, that was what Radio 1 used to do when Moyles and co went out to a non-network studio for a one off show. Not sure how they handled jingles etc.
Do you think that any radio station has CDs these days? Except maybe a few as backup (and the one at the TX site ready to kick in when needed)
As I understand it ViLoR stations do have some sort of backup mixer and presumably some sort of replay device. I'm sure they have a CD player of some sort for when a local musician guest turns up with a disc. But it's not a regular part of their workflow
Guess they'd probably rip it and load it into the VCS and play digitally.
As for jingles etc, I have heard a few setups over the years - from piping the entire output down the line (which sounded a bit ropey), to just having the mics piped into a studio back in London and then having a tech-op fire jingles and play songs.
Interestingly when Moyles was at one of the BBC LR stations I noticed that the cartwall screen they used at R1 followed him, so they probably had a local copy running off a computer with a cached copy of the audio they had back in London and wired the audio of the PC into the studio.
Wouldn't surprise me if with ViLoR any network radio station can easily decamp to the local radio station and be up and running without much issue as the locals are now on Dira. The mic levels on Greg James' show on R1 the other day did sound a bit distorted for some reason, no doubt it was just not set up for him and they just grabbed a studio.
Steve in Pudsey gave kudos