There have been several times that an engine arrived in Antonito was not able to return to Chama the next day. In August 1988, a situation like this occurred and engine #489 run by Russ & Marty Fischer left Chama around 8 pm and arrived in Antonito around 1 am. Here's some video of the event:
#489 night run to Antonito
Back in the later 1990's when I was firing for the C&TS we arrived at Cumbres on a double header and then discovered that the engine out of Antonito was not going to be able to make it to Chama so the helper (#463) was turned on the Cumbres Wye and then backed all the way to Osier with Gerald Blea as engineer and Kyle Norcross as fireman (this was before the loop at Osier existed). By the time we left Cumbres with the passenger train, 463 was already way down Los Pinos canyon.
Earl probably can provide more details and probably knows of several other events...